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    Psychotropic PRN

    medication in inpatient

    psychiatric care: a

    literature review

    Report from the Conflict and Containment

    Reduction Research Programme

    Steve Wright, Institute of Psychiatry, Kings College London

    Duncan Stewart, Institute of Psychiatry, Kings College London

    Len Bowers, Institute of Psychiatry, Kings College London

    September 2012 Section of Mental Health Nursing Institute of Psychiatry London SE5 8AF

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    CONTENTS 1. INTRODUCTION 4

    1.1 Aim 4 1.2 Search method 4 1.3 Definition 4 1.4 Quality appraisal 5 1.5 Data abstraction and synthesis 5

    2. RESULTS 5

    2.1 Prevalence and incidence of PRN use 5 2.2 Good practice in PRN use 9 2.3 Clinical decision-making in PRN use 11 2.4 Demographic profile of patients 13

    2.4.1 Age 13 2.4.2 Gender 14 2.4.3 Ethnicity 14 2.4.4 Interactions between age and gender 15 2.4.5 Marital status 15 2.4.6 Employment status/education 15 2.4.7 Other sociodemographic variables and PRN

    use 16 2.4.8 Diagnosis 16 2.4.9 Admission status 17 2.4.10 Length of inpatient stay 17 2.4.11 Previous admissions 18 2.4.12 Chronic physical illness or disability 18

    2.5 Characteristics of patients receiving repeated PRN doses 18 2.6 Relationship of PRN to regular medication 19 2.7 Temporal ecology of PRN administration 21

    2.7.1 Time of day 21 2.7.2 Day of week 22 2.7.3 Month 22

    2.8 Antecedents of PRN use 22 2.9 Outcomes of PRN use 26 2.10 Relationship of PRN use to other containment m ethods 28 2.11 Alternatives to PRN and their use 29

    2.11.1 Regular medication as an alternative to PRN medication 29

    2.11.2 Non-pharmacological alternatives 30 2.11.3 Is PRN medication actually necessary?

    The case for prohibition 35 2.12 Perceptions of PRN use: staff, patients and ot hers 36

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    3 DISCUSSION 38

    3.1 Summary 38 3.2 PRN use and the City Model 39 3.3 Lessons for future research 40

    4 REFERENCES 42

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    1. INTRODUCTION 1.1 Aim The aim of the review was to evaluate the literature on ‘as required’ (‘pro re nata’ or PRN) psychotropic medication in order to discover evidence which supported or did not support the City Model, and to discover if it highlighted any points not addressed by the City Model. Psychotropic medication is a cornerstone of the treatment of mental disorders, and in inpatient settings it is a key part of the treatment function of admission (Bowers, 2005). Because such medication can take several weeks to be effective (particularly antipsychotic medication), additional medication (which is to say, PRN medication) is commonly needed in the interim in case of agitation and distress. Indeed, between 20% and 50% of psychiatric inpatients receive at least one dose of PRN psychotropic medication during their admission (Chakrabati et al, 2010). The most frequently administered PRN psychotropic drugs are antipsychotics, anxiolytics, hypnotics, and anticholinergics. Despite this important role in the management of acute psychiatric symptoms, the use of PRN psychotropic medication has been criticised on the grounds that it increases risks of morbidity, can be inappropriately used, may result in above-recommended dosages or polypharmacy, and can complicate the assessment of the efficacy of regular scheduled medications, while there are non-pharmacological alternatives to PRN psychotropic medication which are effective and associated with fewer side-effects (Hilton & Whiteford, 2008). 1.2 Search method Electronic searches of the main databases were conducted to locate empirical studies of PRN medication in English published between 1960 and 2011. The databases searched were: PsycInfo, Cochrane, Medline, EMBASE Psychiatry, CINAHL and the British Nursing Index. Key words utilised were PRN or pro re nata or as needed medication or as needed drugs or if needed medication or if needed drugs. Another search was conducted using the key words psychiatr* or mental, inpatient or hospital or ward, psychiatr* and mental, and also inpatient and hospital and ward. The results of the last two searches were then combined. This total was combined with the first search which identified 120 references, which were then inspected for relevance. Review articles, theses, books, and papers concerned with non-psychotropic PRN (e.g. analgesics) or specialities other than inpatient psychiatry, or where PRN medication was included in the calculations of total chlorpromazine equivalents but the prescription and administration was not otherwise investigated were omitted. In total, 84 empirical papers were identified, and all but one (which the British Library was unable to obtain) were reviewed. 1.3 Definition For the purpose of this review, PRN medication is defined as unscheduled psychotropic medication which, when prescribed, may be administered at the nurses’ discretion if the need for it arises. The review focuses on orally-administered PRN medication, although intramuscular PRN medication is sometimes included alongside orally-administered PRN medication in some studies.

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    1.4 Quality appraisal Two of the studies reviewed were trials, but used repeated-measures designs rather than the random allocation of participants to treatment and control arms of a conventional RCT. Thirteen studies were cross-sectional cohort studies using a variety of methodologies (prospective observation, prospective crossover, prospective casenote audit, and point-prevalence surveys). Thirty-two studies were case-control or other comparisons, and 18 were natural experiments without controls. Seven studies were qualitative, again using a variety of methodologies (including interviews, vignettes, and Delphi method), another seven were questionnaire surveys of knowledge or attitudes, and there were three single-case reports. Thirty-seven studies used retrospective casenote audit as their primary data collection method, which is vulnerable to recording biases. The quality of casenote entries can also be extremely variable, and they may not contain a sufficient level of detail for research purposes. Nineteen of the studies reviewed were conducted in the UK. The studies typically had small samples. In the 69 studies involving patients (excluding the single-case studies), the number of participants in them ranged from five to 3,942, with a median of 100 (15 studies collected data on fewer than 50 patients, and five collected data on more than 1,000). For the 11 studies involving non-patients (clinicians, etc.) the number of participants ranged from 18 to 1,226, with a median of 36 (two studies collected data on over 100 non-patient participants, and one on more than 1,000). Twenty-seven studies collected data on patients from only one ward, and 28 collected data from patients on more than one ward in the same hospital. Ten studies collected data from patients from more than one hospital site in the same region, and two collected data from more than one geographical region. In summary, few of the studies employed controls, over a third collected data from an unreliable source, a quarter had fewer than 50 participants, and over 80% of them collected data from a single participating hospital (and in half of theses studies from only one ward), meaning that the data is unlikely to be generalisable. 1.5 Data abstraction and synthesis A structured data extraction tool was created with various headings including sample, methodology, admission status, age, gender, ethnicity, ward type, antecedents/causes, patients’ views, staff views, etc. Where published papers provided empirical evidence, this was entered on the tool. The information contained in the resultant matrix was then summarised for the purposes of this review. 2. RESULTS 2.1 Prevalence and incidence of PRN use As mentioned above, the use of PRN psychotropic medication in inpatient psychiatric units is very common. Table 1 below summarises standardised patient-based rates of PRN use, which are based upon how many patients in a study received PRN medication at least once. These patient-based rates therefore relate to the epidemiological concept of prevalence (the total number of cases in a population). Table 2 summarises the event-based rates, which are based upon the total number of times PRN medication was administered during the study period. These event-based rates therefore correspond to the epidemiological concept of incidence (the rate of occurrence). Overall patient- and event-based rates are presented in the

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    tables, as well as rates which are standardised in relation to number of admissions per month and length of inpatient stay where this information is presented in the studies. None of the studies reviewed gave information about the size of the population served by the units studied, making it impossible to calculate population-based rates. Overall patient-based rates of PRN use range from 4% to 100% of the patients in the study receiving PRN medication at least once, with a mean rate of 52.58%. Table 1. Standardised patient-based rates of PRN ad ministration reported

    in the studies reviewed.

    Patient-based rates

    Paper

    Country

    Ward type

    Overall Per 100

    admissions per month

    Per 100 occupied bed-days

    Mason et al, 1974

    USA VA psychiatric hospital

    44.49%

    Vitiello et al, 1987

    USA Child/adolescent unit

    85.71% 0.12

    Craven et al, 1987

    Canada General psychiatric wards

    75%

    Wise et al, 1989

    USA General hospital 54% 39.13 2.13

    McLaren et al, 1990

    England MSU 46.88%

    O'Reilly & Rusnak, 1990

    Canada University teaching hospital

    64% 4.21

    Ratey et al, 1993

    USA Specialist unit for aggressive patients

    100% 0.27

    Cooney, 1993

    Canada Long-stay unit 57.14% (compulsive

    water-drinkers) 28.57% (controls)

    Craig & Bracken, 1995

    USA Acute, rehab, and elderly wards

    22.92% 22.92

    Haller et al, 1996

    USA Locked inpatient unit

    74% (pre-smoking ban

    average/ month) 60% (post-

    smoking ban average/ month)

    7.14 (pre-smoking ban

    average/month) 4.29 (post-

    smoking ban average/month)

    Milton et al, 1998

    England Acute and forensic

    4% (1994) 5% (1996)

    Kaplan & Busner, 1997

    USA Child inpatient unit

    64%

    Walker, R. (1991).

    USA General hospital psychiatric unit

    70%

    Voirol et al, 1999

    Switzerland One closed psychiatric ward, one open psychiatric ward

    69% (closed ward) 62% (open

    ward)

    Bernard & Littlejohn,

    England Adolescent unit 60.4% 59.9

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    2000 Usher et al, 2001

    Australia Acute 63.33% 63.3

    Thapa, et al, 2003

    USA 3 acute units 78.48% 78.48 4.29

    O'Brien & Cole, 2004

    Australia Acute 17.05% 17.05

    Hales & Gudjonsson, (2004).

    England MSU 64.29

    Zullino et al, 2004.

    Switzerland Detox unit 47.45% (anxiolytics)

    54.55% (hypnotics)

    47.47 (anxiolytics)

    54.56 (hypnotics)

    5.1 (anxiolytics) 5.87

    (hypnotics)

    Russell et al, 2006

    India Child/adolescent service

    26.21 (prescriptions)

    26.09 (prescriptions)

    0.76 (prescriptions)

    Goedhard et al, 2007

    Australia Three long-stay wards

    51.2% 45.49 0.3

    Curtis et al, 2007

    Australia Acute 73.44% 73.44

    Davies et al, 2007

    England 6 acute wards, 3 functional psychogeriatric wards

    44.27%

    Dean et al, 2007

    Australia Adolescent unit 29.23% (pre-intervention) 23.26% (post intervention)

    Stein-Parbury et al, 2008

    Australia Acute 83.8% 83.8 0.04

    Baker et al, 2008

    England Acute 80% 1.14

    Chaichan, 2008

    Thailand Acute 65.7% (pre-intervention) 56.1% (post-intervention)

    65.71 (pre-intervention) 56.01 (post-intervention)

    Philip et al, 2008

    USA Private hospital 69.8%

    Dean et al, 2009

    Australia Adolescent unit 45.45% (time 1) 25.56% (time 2)

    44.69 (time 1) 25.59 (time 2)

    Winterfield et al, 2009

    France Child/adolescent unit

    27.7% 27.66 1.18

    Baker et al, 2010

    England 11 older adult wards

    16.9%

    Swart et al 2011

    Canada Regional children’s unit

    50.3% 50.31 0.6

    Event-based rates of PRN medication use range from 0.61% to 5632.12%. The distribution of rates is J-shaped, heavily skewed towards smaller values, with a median event-based value of 365.42%.

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    Table 2. Standardised event-based rates of PRN admi nistration reported in the studies reviewed.

    Event-based rates

    Paper

    Country

    Ward type

    Overall Per 100

    admissions per month

    Per 100 occupied bed-

    days Vitiello et al, 1987

    USA Child/adolescent unit

    2577.55% 3.51

    Craven et al, 1987

    Canada General psychiatric wards

    2029.333%

    Thorward & Birnbaum, 1989

    Canada General hospital psychiatric unit

    10.41% (pre-smoking ban) 12.74% (post-smoking ban)

    93.23 (pre-smoking ban) 97.38 (post-smoking ban)

    107.83 (pre-smoking ban) 142.26 (post-smoking ban)

    McLaren et al, 1990

    England MSU 712.5%

    Garrison et al, 1990

    USA Child psychiatric unit

    2.85 284.85 6.9

    Walker, 1991

    USA General hospital psychiatric unit

    499.28%

    Ratey et al, 1993

    USA Specialist unit for aggressive patients

    1276% (pre-treatment) 964% (post-treatment)

    3.5 (pre-treatment) 2.64 (post-treatment)

    Cooney, 1993

    Canada Long-stay unit 152.38% (compulsive water-drinkers) 76.19% (controls)

    Fishel et al, 1994

    USA 1 locked university medical centre inpatient unit, 1 locked the other at a state hospital psychiatric unit

    323.64% (state hospital) 462.96% (medical centre)

    Craig & Bracken, 1995

    USA Acute, rehab, and elderly wards

    0.61% 61

    Hoff et al 1996

    USA Rehab 1380% (baseline) 950% (after 3 months of treatment)

    15.16 (baseline) 10.44 (after 3 months of treatment)

    Gray et al, 1996

    England Two acute wards

    1011.36%

    Kaplan & Busner, 1997

    USA Child inpatient unit

    744.67%

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    Gray et al, 1997

    England Two acute wards

    1011.4%

    Bernard & Littlejohn, 2000

    England Adolescent unit 407.2% 404

    Usher et al, 2001

    Australia Acute 297.77% 287.77

    Thapa, et al, 2003

    USA 3 acute units 812.56 812.56 44.1

    O'Brien & Cole, 2004

    Australia Acute 135.23% 135.23

    Alexander, 2006

    England Two acute wards

    516.66%

    Thomas et al 2006

    Australia 2 locked high-dependence units

    241.03 (control) 107.69 (treatment)

    49.47 (control) 11.05 (treatment)

    Megna et al, 2007

    USA Rehab 761.54% (baseline) 161.54% (after 6 months of treatment)

    4.17 (baseline) 0.89 (after 6 months of treatment)

    Goedhard et al, 2007

    Australia Three long-stay wards

    35.42% 3543.8 20.83

    Curtis et al, 2007

    Australia Acute 482.81% 4.83

    Davies et al, 2007

    England 6 acute wards, 3 functional psychogeriatric wards

    28.48%

    Stein-Parbury et al, 2008

    Australia Acute 921% 921 45

    Baker et al, 2008

    England Acute 1382.86% 19.76

    Chaichan, 2008

    Thailand Acute 154.29% (pre-intervention) 136.59 (post-intervention)

    154.29 (pre-intervention) 136.59 (post-intervention)

    Smith et al, 2008

    USA 9 state psychiatric hospitals

    5635.12 (first month of study) 1156.46 (final month of study)

    Dean et al, 2009

    Australia Adolescent unit 223.21% (time 1) 110.73% (time 2)

    221.24 (time 1) 108.23 (time 2)

    Winterfield et al, 2009

    France Child/adolescent unit

    0.81% 80.85 3.44

    Baker et al, 2010

    England 11 older adult wards

    49.35%

    Swart et al 2011

    Canada Regional children’s unit

    59.5% 494.85 5.95

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    More than three-quarters of the event-based rates are in excess of 100%, which indicates that some patients received more than one dose of PRN medication. The clinical characteristics of patients receiving large numbers of PRN administrations are summarised below. 2.2 Good practice in PRN use A Delphi study by Baker et al (2007a) explored multidisciplinary opinions concerning issues and best practice for the prescribing and administration of psychotropic PRN medication in acute inpatient psychiatric settings. The consensus statements generated converged into 4 key themes, which represents a convenient basis for describing best practice as found in the studies reviewed. Service users should be more involved in all proces ses concerning PRN. This should be individualised, involving joint decision- making, negotiation, and should whenever possible take account of advance di rectives and preferences: None of the articles reviewed had user involvement as its primary focus, although half of the participants in Baker et al’s (2007b) qualitative study of clinicians’ PRN medication practices reported that their decision to prescribe or administer PRN was influenced by patient preferences, and half of the clinicians reported providing some information about PRN to patients, although the content of this was limited, and it appeared that patients usually only received additional information if they asked. Information provision on side effects was particularly scarce, and was often only given when staff did not want a patient to take a particular medication. In an earlier qualitative study of service users’ experiences of PRN medication (Baker et al, 2006), participants reported feeling empowered by being able to decide about the timing and dose of extra medication, making them feel more in control. However, participants also reported that the process associated with the use of PRN was confusing and stigmatising, and expressed anger, frustration and embarrassment at refusals of medication that they had requested. Such refusal was seen as disempowering, especially when not accompanied by an explanation from staff, or if they took place in public ward areas. Some participants also reported not being informed that PRN medication had been prescribed. In Baker et al (2010) no indication was found in any of the casenotes of patients who had received PRN medication to the effect that information had been given to the patient. Prescribing and administering PRN should be based o n assessment, leading to a clear, proactive indication for use in the prescr iption. When administered, PRN should be for the reason it was prescribed. Ind ications for use therefore need to be clear and agreed by all: Participants emphasised the importance of assessment in Baker et al (2007b), although they also reported that haloperidol and lorazepam were routinely prescribed as PRN without assessment. More specifically, participants in Usher et al (2009) emphasised that the prescription and administration of PRN medication should be based upon thorough assessment of the patient, and thorough knowledge of the patient and background factors. Lack of clarity of indications for PRN use is also noted among the studies reviewed. Craven et al (1987) found that no indication for use was specified in 47% of prescriptions, and when indication for use was not specified 11% of PRN prescriptions were administered for different reasons on different occasions, and Walker et al (1991) found that 30% of the patients in their study had a prescription which did not specify any indication for the drug. In addition to absence of indications for use in PRN prescriptions, Baker et al (2007a) found that 71% of the clinicians interviewed had encountered occasions where PRN medication had been used for reasons other than the prescribed indication for use, and it was also commonly found

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    among the studies reviewed that the reason why PRN medication was administered was not recorded in casenotes. This is discussed in more detail below. The studies reviewed also note more general problems with PRN prescriptions than discussed here. Those concerned with the possibility of PRN medication possibly contributing to accidental high doses and polypharmacy are also discussed below, but other problems include lack of a clearly indicated total 24-hour dose (Walker, 1991; Baker et al, 2010), and generally poorly written (or even illegible) prescriptions (Adamson, 1995; Baker et al, 2007b; Usher et al, 2009). Prescriptions should be time-limited, thereby encou raging the process of review, which should include evaluation of the effe ctiveness and treatments and take into account service users' experience of taking PRN: It was also commonly reported among the studies reviewed that PRN medication prescriptions were not time-limited, or were not subjected to regular review. Mason & Dewolfe (1974) found that 36% of antipsychotic PRN prescriptions had been written by a previous doctor to their current one, and that 89% of PRN prescriptions had been in place for between one and six months without being re-written, despite the hospital policy to re-write prescriptions at least once per month. Craven et al (1987) found that only a quarter of 25% of PRN prescriptions were directly stopped by doctor, with the remainder being allowed to expire. Participants in Baker et al (2007b) suggested that the review process for PRN appeared vague, and that reviews that included PRN were infrequent. A clear trigger for review was when nursing staff identified a problem - the most commonly cited one being when additional doses of PRN were needed or if there were concerns that a patient might be an "addict" (especially benzodiazepines, but also procyclidine). The issue of misuse of PRN medication by patients is also raised in Usher et al (2009), and is discussed in more depth in D’Mello et al (2000) and Schaefer et al (2011). The evaluation of the effectiveness of PRN medication is hampered by lack of reporting and by poor definitions of effectiveness that are common among the studies reviewed. This issue is discussed in more detail below. Staff need to develop knowledge and awareness about potential side effects prior to using PRN: Problems were also identified in the studies reviewed concerning staff knowledge and awareness about potential side-effects of PRN, as well as other safety concerns. Birmingham et al (1999) found that, while nurses participating in their study of the use of PRN antimuscarinic medication emphasised the importance of objective assessment for antipsychotic-induced side-effects prior to administering antimuscarinics, and demonstrated a good working knowledge of acute extrapyramidal side-effects, many also indicated that they would administer antimuscarinics for other reasons. For example 42% said that they would give PRN procyclidine to a patient complaining of a dry mouth, and 36% said they would give it for blurred vision. Both of these side-effects would have been worsened by antimuscarinics. Nearly half of the participants said that they would treat tardive dyskinesia with antimuscarinics, although these would have no value in treating this side-effect. Usher et al (2010) found that while most responses were in keeping with accepted guidelines and accepted practice, many answers given by clinicians responding to clinical vignettes involving PRN use indicated a lack of knowledge of best practice (including extremely high dosages of benzodiazepines, inappropriate administration of risperidone in an elderly patient, administration of PRN medication secreted in food, inconsistent adherence to guidelines, and lack of awareness of special needs of certain groups). This might be attributable to shortcomings in training highlighted in an earlier study (Usher et al, 2010), in which participants reported that their pre-registration training had not provided sufficient information to assist with the decision-making surrounding PRN, and gave little indication of opportunities to update knowledge through in-service or formal education.

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    2.3 Clinical decision-making in PRN use. Baker et al (2007b) reported that decisions to administer PRN medication were often reported to be based around patient history, mental state, and risk assessment, although as mentioned above, certain medications appear to be prescribed routinely for PRN use, irrespective of these considerations. Safety, knowledge of the patient, and the patient’s level of distress were all mentioned as influential by the participating clinicians. Nearly all of the participants reported that nurses influenced the prescribing practices of medical staff (particularly junior doctors), which usually involved obtaining higher doses of typical antipsychotics, and, on occasions, prescriptions for Acuphase. In contrast, very few nurses reported that their decisions to administer PRN were influenced by medical staff. Baker et al also report an impression that a particular sub-group of nurses (termed “the old school”, which were often, but not exclusively, night staff) who administered PRN more frequently, as did those who had experienced adverse events (e.g. assault) or who frequently secluded patients. Decision-making was also highlighted in Usher et al (2009), where the patient’s level of distress, agitation, aggression, and psychosis, concern for the safety of the patient or for others in the environment, and patients’ requests were cited as influencing the decision to administer PRN medication. Most of the participants also emphasised that PRN medication should only be administered when other alternatives had been tried and found unhelpful. This topic featured in several of the studies reviewed, and is discussed more fully below. Participants also made suggestions for improving practice, which mainly concerned improving the clarity, adequacy, and accuracy of prescriptions, access to up-to-date information, and emphasising the importance of awareness of safety of patients and others in the ward environment. Usher et al (2009) also report environmental factors that influenced decision-making, including the mental state of other patients on the ward, (especially if these included numerous psychotic or agitated patients), staffing levels (being short-staffed was given as a reason for high levels of PRN use), and the use of casual staff who were less likely to be familiar with the patients. The more contextual factors affecting clinical decision-making in PRN use were explored by Sonntag et al (2006) in their study of the use of sedative drugs in nursing homes for older patients. They found that 54% of the probability of the administration of PRN sedatives depends on institutional characteristics such as low perceived competence of the staff, high ratio of unqualified staff to residents, and increased average level of patient disturbance on the ward. Furthermore, when these factors were entered into the model, 32% of the variance remained, suggesting that a substantial number of unidentified institutional characteristics were also exerting an effect. Baker et al (2008b) attempted to improve upon clinical practice by means of an intervention study which used a good practice manual based upon previous research and guidelines (Medical Research Council, 2000; Baker et al 2006; Baker et al 2007a, 2007b; Baker et al, 2008a). The following themes were included in the manual:

    1. Considering the patient (knowledge, preferences and choices). 2. Improving prescription quality. 3. PRN as part of the clinical management plan. 4. Evaluating the effects and side-effects of PRN. 5. Frequent review of PRN. 6. Enhanced documentation by the multidisciplinary team. 7. Preventing distress when using PRN.

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    8. PRN as a last resort encouraging the use of non-pharmacological interventions.

    9. Additional training and education is required for all staff. Data on PRN use on two acute inpatient wards were collected for a four-week period. This was followed by a two-week period to allow staff to become familiar with and to incorporate the principles outlined in the manual into their clinical practice, and then data was then collected for a further four-week period. The manual was favourably received by the clinical team (with many members of it indicating that it had changed their clinical practice), the types of drugs administered PRN were found to have changed significantly (reduced benzodiazepines and antipsychotic use, and increased use of hypnotics), and provision of information and educating patients regarding PRN medication also improved significantly. However, the mean quality score for nursing notes reduced significantly over the study period, non-documentation of PRN administration increased (although not significantly) and medication errors (beyond poor prescribing quality) were found in the notes of nearly two-thirds of the patients. 2.4 Demographic profile of patients An aim of the review was to establish a profile of patients who were subjected to PRN psychotropic medication. Particular reference was made to age, gender, ethnicity and diagnosis, although other variables were also examined. 2.4.1 Age: Age differences between patients who are prescribed and/or have

    received PRN psychotropic medication are commonly reported in the literature, but comparatively few papers report the statistical significance of them. Benson (1986) found that patients aged 25 to 44 years were significantly more likely than older patients to be prescribed PRN psychotropics, and the multivariate model used found that age was the only significant patient demographic variable, which was negatively associated with the likelihood of having PRN psychotropics prescribed. This is described as clinically appropriate, as large doses of psychotropic medication for older patients is discouraged because they are less tolerant of it and require less to derive a therapeutic effect. Benson also found that when level of impairment was taken into consideration, the relationship between patient age and PRN medication disappeared, indicating that severely symptomatic patients were likely to receive PRN medication irrespective of age. Another prescription-only study (Hales & Gudjonsson, 2004) also found that younger age on admission was significantly associated with PRN psychotropics being prescribed on admission, which was thought to possibly reflect doctors’ perceptions that younger patients would be more likely to need PRN medication than older patients. Again, the actual administration of PRN psychotropics during the patients’ inpatient stay did not feature in this study. An earlier study of PRN administration patterns in a Regional Secure Unit (McLaren et al, 1990) found that patients who received PRN psychotropics were significantly younger than those who did not (mean age 29.5 years vs. 33.1 years). Possible reasons for this are not discussed. Winterfield et al (2009) studied both prescription and administration of PRN psychotropics in a child and adolescent psychiatric service, and found that while older patients were significantly more likely to be prescribed PRN psychotropics, there was no significant age difference between those who actually received them and those who did not. Again, possible reasons for the age difference in relation to prescribing are not explored, but the lack of age difference for PRN administration was though to

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    be due to the interactions between patients and staff, and staff variables such as age, gender, and staff training which were not considered in the study.

    Two other studies reviewed found younger age to be significant. Geffen et al (2002) found that, while age was not associated with the administration of PRN antipsychotics, younger patients received significantly higher doses, while Philip et al (2008) report that patients receiving PRN quetiapine were slightly (but significantly) younger (mean age 39 vs. 40 years). Neither study discusses possible explanations for this finding.

    In contrast, Craven et al (1987) found that being aged 50 or over was significantly associated with the rate of both PRN psychotropic prescription and administration in general, and with the rate of prescription and administration of PRN sedative-hypnotics The authors consider that this may be because of a higher frequency of night-time insomnia among older patients, or because older patients are not considered by clinicians to be amenable to non-pharmacological interventions for insomnia. This finding is partially mirrored by O’Reilly & Rusnak (1990), who report that patients receiving PRN sedative-hypnotics were significantly older than those who did not (mean age 37.9 years vs. 25.1 years). While acknowledging this increased use of hypnotics among elderly patients, the authors point out that none of the geriatric patients in the study were given hypnotics, and that hospital policy strictly regulated the use of such drugs. However, no explanation of the age-related finding among the non-geriatric patients is offered.

    Where significant differences are reported, findings regarding the relationship between age and PRN psychotropic medication are mixed.

    2.4.2 Gender: Only two of the studies reviewed found any significant relationship

    between gender and PRN psychotropic medication. While Geffen et al (2002) found no gender-related differences in frequency of PRN administration, male patients did receive higher daily doses of PRN antipsychotics, and Winterfield et al (2009) report that while female child and adolescent psychiatric patients were more likely to have PRN prescribed (51% of female patients vs. 21% of male), no significant gender difference was found between patients administered PRN psychotropics and those not. Once again, Geffen et al do not discuss possible reasons for this finding, while Winterfield et al again attribute it to interactions between patients and staff, and staff variables such as age, gender, and staff training.

    Where significant gender differences are reported, gender does not appear to have a relationship with the administration of PRN psychotropics as such, although adolescent female patients seem to be more likely than adolescent males to be prescribed them, and adult male patients receive higher daily doses.

    2.4.3 Ethnicity: Three of the reviewed studies reported significant differences

    concerning PRN psychotropic medication and ethnicity. Flaherty & Meacher (1980) found that they were more frequently administered to Black patients than to White patients, possibly because of a stereotypical view of Black patients as dangerous leading to the use of more restrictive containment methods. The Black patients were not thought to be in fact larger or stronger than the White patients, so this was not in itself thought to be a reason for the observed higher frequency of PRN administration. Benson (1986) reports that

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    non-White patients with a high level of psychiatric impairment were significantly more likely to be prescribed PRN psychotropics which he notes as consistent with earlier findings. However, because dangerousness itself was no assessed in the study, it was impossible to ascertain whether Black, highly impaired patients did in fact present a higher level of risk than highly-impaired White patients, although Benson does suggest that racial stereotypes influence (typically White) psychiatrists’ views that this patient group is particularly problematic and in need of additional medication. This view is also found in Usher et al (2009), in which medical and nursing staff identified being a young, male, and indigenous Australian as a predictor of being administered PRN medication. Usher et al suggest that this could be due to the manner in which the behaviour of indigenous Australian men is interpreted by clinicians, a failure to engage such patients in meaningful treatment discussions, and/or due to a higher level of acuity on admission found among such patients. Whatever the reason, cultural identity was seen as a clear influence on the decision to use PRN psychotropics, and this bias was noted as consistent with previous research which suggests that Anglo-European and White North American clinicians are more likely to interpret as threatening or aggressive when it is displayed by non-White patients. Bernard & Littlejohn (2000) also report that significantly more non-White patients received PRN psychotropics than White patients in an adolescent unit, and that, of all individual ethnic groups, African-Caribbean patients were most likely to be prescribed them. However, while noting that this is an issue of interest and concern, the authors consider that their sample was too small to draw clear conclusions from. Interestingly, Hales & Gudjonsson (2004) who specifically examined the issue of ethnic differences in the use of PRN medication found no such relationship.

    Black patients appear to be significantly more likely to receive PRN psychotropics than White patients, which may be because racial stereotypes influence psychiatrists’ views that this group of patients is particularly problematic and therefore needs additional medication, but could also be due to a higher level of acute symptoms on admission in Black patients.

    2.4.4 Interactions between age and gender: Swart et al (2011) report the only

    significant interaction effect between variables found in all the studies reviewed. They found that among patients who received PRN psychotropics, younger male patients were significantly more likely to have received PRN than female patients, while older female patients were more likely to have received PRN than male patients.

    2.4.5 Marital status: Only one study (Benson, 1986), reported significant findings

    concerning the relationship between PRN psychotropic medication and marital status. Although he found that unmarried patients were significantly more likely to receive PRN psychotropics than married patients, possible reasons for this association are not discussed.

    2.4.6 Employment status/education: None of the studies reviewed investigated

    or commented upon any relationship between PRN medication use and employment status. The only study which mentioned any relationship between PRN use and education level was by Evans & Di Scipio (1980), who found that academic achievement did not distinguish between adolescent inpatients who received high (but unspecified) numbers of PRN administrations and those who did not.

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    2.4.7 Other sociodemographic variables and PRN use: None of the studies reviewed mentioned any relationship between PRN psychotropic medication and the patient sociodemographic variables of religion, country of origin, accommodation, or living arrangements, nor made any reference to PRN psychotropics with regard to patients’ family or family life.

    2.4.8 Diagnosis: Just over half of the papers reviewed which reported significant

    associations between PRN psychotropic prescribing and administration and diagnosis were conducted in child and adolescent settings. Three out of the five papers concerning research in these settings found that developmental disorders were significantly associated with PRN use. Vitiello et al (1987) found that psychiatric diagnosis as such did not predict number of PRN administrations, but patients with moderate learning disability received significantly more PRN administrations than patients with no learning disability, mild LD and severe LD. They also found that 70% of PRN doses were in response to aggression and disruptive behaviour, and while this might account for why patients affected by more severe learning disability received fewer doses (these patients are described as more passive and dependent, and therefore less disruptive), no explanations are discussed concerning why less PRN medication was administered to the patients with mild learning disability. Dean et al (2006) also reported that significantly more doses of PRN were administered to patients with pervasive developmental disorder, ADHD, and mental retardation, as well as patients with a greater number of comorbid diagnoses, and consider that this might be because PRN is utilised in more complex patients where impulsive behaviour is a feature. Echoing this, Swart et al (2011) found that children with DSM Axis II intellectual disabilities, besides receiving significantly more PRN than patients diagnosed with Axis I mental disorders, were more likely to receive PRN in response to risk of self-injury or space issues, and having received one PRN dose, were more likely to receive future doses than patients with Axis I disorders. This was attributed as due to the impairment of learning potential and executive function in people with developmental disabilities. Winterfield et al (2009) report that very few patients with learning disorders (undefined in the paper, but different to learning disability) received PRN medication, but since almost half of these patients were treated in the partial hospitalisation facility (essentially a day unit), they were therefore less likely to be disruptive than the inpatients.

    Regarding adult patients, participants in Usher et al (2009) identified patients who displayed signs of aggression/agitation, or had either a psychotic disorder or elated mood as more likely to receive PRN medication, which was largely echoed in the quantitative papers that were reviewed. For example, Benson (1986) found that patients with schizophrenia and with chronic mental disorders were significantly more likely to be prescribed PRN, while patients with low to mild levels of psychiatric impairment were less likely to be prescribed PRN, and were prescribed significantly lower doses. Craven et al (1987) found rather different associations between PRN prescription and diagnosis, in that a diagnosis of personality disorder was significantly associated with rates of PRN prescription and administration, and with rates of prescription and administration of PRN neuroleptics and sedative-hypnotics. PRN neuroleptic medication was also found to be significantly associated with mania, as was the rate of PRN administration in general. The prescription of PRN antiparkinsonian medication was significantly associated with schizophrenia, mania and personality disorder (probably reflecting prescribing practices in line with the association of PRN neuroleptic

  • 17

    prescriptions for these diagnoses). Geffen et al (2002) reported that patients with mania/mixed affective psychosis and schizophrenia-related disorders received significantly higher PRN doses than patients with depression, and that patients with mania/mixed affective psychosis received significantly higher doses of PRN benzodiazepines than patients with schizophrenia. In contrast, Walker (1991) found no significant relationship between PRN administration in general and diagnosis, although he found that manic patients and patients with schizophrenia less likely to receive PRN hypnotics than patients with major depression. While patients with anxiety symptoms were significantly more likely to receive PRN anxiolytics, patients with psychotic symptoms were as likely to receive anxiolytics as antipsychotics, which may reflect Walker’s finding that anxiolytics were more likely to be judged effective in alleviating patient distress, and the fact that improvement can be achieved more safely with anxiolytics because they have a more benign adverse effect profile than antipsychotics. With specific regard to PRN quetiapine, Philip et al (2008) found that only 17.4% of patients receiving it had indicated diagnoses (schizophrenia and bipolar affective disorder), and concluded that it was being used as a treatment for agitation when clinicians were reluctant to use benzodiazepines or conventional antipsychotics.

    Among child and adolescent inpatients. PRN psychotropic use appears to be associated with developmental disorders rather than DSM Axis II mental disorders. In adults, most of the studies reviewed which examined psychiatric diagnosis and PRN use found it to be associated with psychotic disorders (particularly schizophrenia), mania, and personality disorders, which probably reflects the use of PRN medication in containing impulsive, erratic, and possibly dangerous behaviour.

    2.4.9 Admission status: Curtis et al (2007) was the only paper reviewed which

    reported a significant finding concerning the legal status of inpatients receiving PRN psychotropics. They found that all the patients who received more than 10 PRN administrations during the study period were detained patients, and that mean number of PRN administrations in detained patients was more than double than that of informal patients. This finding was statistically significant, and suggests an association.between formally detained patients and PRN medication use. However, Craven et al (1987) found no significant relationship between admission status and ether the rate of prescription or rate of administration of PRN psychotropics.

    2.4.10 Length of inpatient stay: Five of the papers reviewed report significant

    relationships between PRN psychotropic use and length of inpatient stay, four of which are studies undertaken in child and adolescent units. Bernard & Littlejohn (2000), Dean et al (2006), Winterfield et al (2009), and Swart et al (2011) all report that PRN use and length of inpatient stay are positively related. Winterfield et al additionally report that female patients were more likely to receive PRN medication for the first time later in their admission than male patients, and that children with developmental disabilities tended to receive PRN for the first time earlier in their admission than children with Axis I diagnoses. However, Swart et al found that, on the same age level, female patients had 15% higher odds to receive their first PRN medication earlier than male patients, and Vitiello et al (1987) found that the number of PRN administrations did not correlate with length of stay. In their study of the use of PRN sedative-hypnotic medication in a general hospital setting, O’Reilly and Rusnak (1990) found no correlation between length of stay and PRN administration among the adult psychiatric patients. Bernard & Littlejohn

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    attribute the fact that admissions involving PRN medication were significantly longer than those with no PRN use to the nature and severity of problems leading to admission. However, direct measures of the severity of psychopathology were not used in the study, which is a weakness of many of the studies reviewed. They also report that significantly more PRN psychotropics were administered in the first quarter of the admission, which supports the idea that PRN is used as a response to agitated, aggressive and impulsive behaviour, as this is more likely to be seen early in the admission before treatment has started to become effective. Several other studies in adult inpatient settings also report more frequent PRN use early in the admission, although the rates of use vary widely. Fishel et al (1994) report the statistically significant finding that nearly 78% of PRN medication was administered in the first four days of admission, but do not discuss possible reasons for this. Gray et al (1996) found that just over 38% of PRN was administered in the first four days of admission, and frequency of PRN use decreased throughout the course of the admission, and Usher et al (2001) found that PRN was more likely to be administered on the first and second day of admission, with a reduction in likelihood of administration after day nine. Similarly, Curtis & Capp (2003) reported that most common day for the initial administration of PRN was the day of admission, and while they report a ‘significant’ decrease from the second day, no statistical significance level is reported. Chaichan (2008) found that over half of the mean total number of PRN administrations were given in the first three days after admission, with the rest being administered throughout the remainder of it, and over half of the mean total chlorpromazine equivalent of PRN medication received was also administered in this period. Unfortunately, none of these three studies report significance levels for their findings.

    Most PRN psychotropics use usually occurs in the early stages of admission, and becomes less frequent throughout the admission’s duration.

    2.4.11 Previous admissions: Only one study reviewed, Craven et al (1987),

    commented upon the possible relationship between number of previous admissions and psychotropic PRN use. The number of previous admissions was found not to affect the rate of PRN administration in general, but it was significantly associated with the rate of administration of PRN antiparkinsonian medication. This was thought to be because nurses recognise or anticipate early signs of parkinsonian side-effects in patients that they knew from previous admissions who had received neuroleptic medication, or because the patients who had experienced these symptoms in previous admissions might recognise them more readily, and ask for PRN antiparkinsonian medication.

    2.4.12 Chronic physical illness or disability: None of the studies reviewed

    commented upon any relationship between PRN psychotropic use and patients with chronic physical illnesses or disabilities.

    2.5 Characteristics of patients receiving repeated PRN doses As mentioned above when discussing rates of PRN use, many patients receive more than one dose of PRN medication. In the studies reviewed it was commonly reported that a relatively small proportion of the patients received a large proportion of the PRN mediation that was administered. The proportion of high-PRN patients varies from study to study, and different studies define high PRN use differently and have study periods of differing duration. None of the studies reviewed reported the

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    statistical significance of observed proportions of patients receiving high levels of PRN medication compared to those who did not. Baker et al (2008) report that of the 35 patients who received PRN medication, 11% received 50 or more PRN administrations in the 10-week study period. Thapa et al (2003) found that the 14% of patients who had received PRN medication over a three-month period accounted for 54% of the PRN doses administered. In Curtis et al (2007), nearly a quarter of patients who received PRN medication over a one-month period received 10 or more administrations during the month, and collectively accounted for just over 46% of PRN administered. Stein-Parbury et al (2008) found that less than 3% of patients in their study received 40 or more PRN doses during their admission. These patients had diagnoses of schizophrenia (39%), schizoaffective disorder (33%) and bipolar affective disorder (28%). Another study finding a link between a small group of patients receiving repeated PRN doses and psychosis is McLaren et al (1990). While no overall relationship between diagnosis and PRN use was observed, four patients out of the 12 with a diagnosis of schizophrenia accounted for 52% of PRN administrations. Craig & Bracken (1995) also found that schizophrenia was the predominant diagnosis among the 27 patients (2.8% of the hospital population) who accounted for 44.4% of unscheduled medication (PRN and stat doses) administered in a one-month study period. These patients received an average of 9.7 doses of PRN each, 59% of them had a diagnosis of schizophrenia, 59% were aged over 40 years, and 52% were men. The disproportionate amount of PRN use found among a relatively small group of patients is also reported in child and adolescent psychiatry, as is a relationship with aggressive behaviour and psychosis. Vitiello et al (1987) found that 18% of inpatients who received PRN psychotropics had received over 50 PRN doses each. While the actual number of doses that this group of patients received is not given, even if a figure of only 50 PRN doses each is assumed, this still accounts for 27.7% of PRN doses administered in the one-year study period. Bernard & Littlejohn (2000) found that PRN psychotropics were administered more than 10 times in 11% of admissions, accounting for 60% of PRN doses administered. While psychiatric diagnosis was not recorded in this study, the authors believe that this group of patients who received high levels of PRN medication was characterised by histories of extremely antisocial and aggressive behaviour prior to and during their admissions. This echoes Evans & Di Scipio’s (1980) finding that the 10 patients who had received the most PRN administrations (number unspecified) were characterised by pre- and post-admission histories of violence and a diagnosis of a psychotic disorder. 2.6 Relationship of PRN to regular medication PRN medication is frequently prescribed alongside regular medication during inpatient admissions. Craven et al (1987) found that 97% of PRN prescriptions were in addition to prescriptions of regular psychotropic medication. More recently, Geffen et al (2002) reported that, when regular and PRN medications were combined, 76% of admissions involved prescription of two or more antipsychotics and 38% two or more benzodiazepines. Concomitant PRN medications accounted for 31% of the total antipsychotic dose and 28% of the total benzodiazepine dose in patients who received them by schedule. High rates of prescription and administration of regular and PRN psychotropics are also reported in child and adolescent psychiatry. Vitiello et al (1987) found that the number of PRN administrations was significantly correlated with dose of regular neuroleptics. In Kaplan & Busner (1997), high proportions of patients in three different child psychiatric hospitals settings who were on regular antipsychotics also received PRN or stat doses of antipsychotics (although no statistically significant differences were found between the state, private, or

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    county-university hospitals). Winterfield et al (2009) found that 67% of patients who were prescribed PRN medication were already receiving regular psychotropics. In relation to the risk of PRN medication and polypharmacy among child and adolescent inpatients, Dean et al (2006) report that patients receiving a larger number of concomitant medications at admission were significantly more likely to be prescribed PRN, and that patients receiving polypharmacy received a significantly greater number of PRN doses, while Russell et al (2006) found that PRN medication increased the risk of polypharmacy among child and adolescent inpatients. Thapa et al (2003) comment that PRN medication may expose psychiatric inpatients to unnecessary psychotropic medications, and that, given the potency of these agents, this can increase the risk of significant side-effects (Ayd, Jr, 1985). Because PRN psychotropics are typically prescribed as an adjunct to regular psychotropic medication, if they are administered there is a risk of causing morbidity through contributing to a high (and potentially toxic) dose. Another risk is that when combined with regular medication, PRN medication might cause harmful pharmacokinetic drug interactions and other adverse effects through polypharmacy. Milton et al (1998) examined changes in antipsychotic prescribing in two surveys of psychiatric inpatients conducted eight and 32 months after the publication of a Royal College of Psychiatrists’ Consensus statement on the prescribing of high-dose antipsychotics (Thompson, 1994). This states that only fully-qualified psychiatrists (MRCPsych) should recommend the prescribing of antipsychotic medication above British National Formulary advisory limits. They found that when PRN prescribing (usually by junior doctors) is included with regular prescriptions, mean potential doses and the numbers of patients who might receive high doses increases substantially. While both the mean chlorpromazine equivalent doses and the proportion of patients receiving high-dose antipsychotics (including PRN) fell between the two surveys (from 1,359mg/day to 1,138mg/day, and from 47% of patients to 39%), the statistical significance of these reductions is not reported. While the actual administration of prescribed PRN was uncommon (4% to 5% of prescriptions, suggesting that injudicious prescribing is less clinically relevant than supposed), the potential still exists for unwittingly-administered high doses. Another audit by Bowden (1999) also found that PRN medication prescriptions were a significant source of potential high dosage, although only one patient out of a potential eight actually received PRN medication leading to exceeding the maximum dose, while one other patient reached the maximum dose. While the Consensus Statement recommends that ideally the same drug should be prescribed for regular and for PRN doses, that only one antipsychotic drug should be prescribed PRN, and that PRN medication should be prescribed at a specific rather than a ranged dose, Bowden reports that only 42% of patients with a regular antipsychotic and a PRN antipsychotic prescription were prescribed the same drug, five patients were prescribed two PRN drugs (and one was prescribed three), and 80% of antipsychotic PRN prescriptions gave ranged doses. A number of measures were implemented to improve prescribing, and on re-audit six months later both the number of prescriptions for a ranged dose of PRN and the number of prescriptions for different regular and PRN drugs had fallen significantly. While the number of patients prescribed more than one PRN drug had fallen from 10% to 2%, this was not found to be significant, probably because of the small number of patients concerned. Both Milton et al (1998) and Bowden (1999) report studies of geographically-restricted services which may not be readily and more widely generalisable. Paton et al (2008) invited all NHS trusts and private healthcare providers in the UK that provide specialist mental health services to participate in a quality-improvement project focussing upon high-dose and combination (more than one drug prescribed)

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    antipsychotic prescribing in acute wards. In total, 32 services participated, submitting data on 3,942 patients at baseline and 3,271 patients at re-audit one year later. Little change was found in the prevalence of high-dose prescribing (36% at baseline, 34% at re-audit) or combined prescribing (43% at baseline, 39% at re-audit), with PRN prescribing being the principal cause of both high-dose and combined antipsychotic prescribing at both timepoints. In terms of the risk of morbidity due to high dosage from combined PRN and regular medication doses, Geffen et al (2002) found that both receipt of PRN medication and greater frequency of PRN administration were significantly associated with morbidity, which was also significantly associated with the receipt of both PRN antipsychotics and benzodiazepines. The contribution made by PRN antipsychotics to medication-related morbidity is highlighted in this study, as the mean daily dose of haloperidol observed represented a substantial contribution to the total daily antipsychotic dose. While extra-pyramidal symptoms were the most frequently recorded type of medication morbidity (which was also significantly related to PRN administration), a relatively low rate of such symptoms were observed (15%). This is probably because the methodology employed (retrospective casenote review) underestimated the true prevalence (compared to active screening for such symptoms). Davies et al (2007) examined the risk potential of PRN medication causing dangerous pharmacokinetic drug reactions when administered alongside regular medication. Prescription-chart data were collected from 323 psychiatric inpatients in a British city in order to establish the prevalence of PRN prescription and administration, and to assess the potential for interactions involving CYP2D6 and CYP3A4 between drugs prescribed and administered. CYP2D6 and CYP3A4 are the most important CYP enzymes involved in psychotropic drug elimination (Pollock, 1994), metabolising many psychotropic drugs that are prescribed for both regular and PRN administration. Because several drugs are potent inhibitors of CYP activity, the slowing of metabolism that they cause increases plasma concentrations and increased adverse effects (Vandel et al, 1995). Overall, 117 combinations of drugs were found that could give rise to clinically active CYP2D6 or CYP3A4 interactions. Of these, 84 combinations involved drugs prescribed for PRN administration, and 66 patients (20%) had at least one potentially clinically important CYP2D6 or CYP3A4 combination which involved one or more PRN drugs. 2.7 Temporal ecology of PRN administration Significant findings concerning days of the week or time of day at which peak PRN use is observed might suggest changes to working practices that might reduce the need for PRN medication. However, statistically significant findings on this subject are the exception among the papers reviewed. 2.7.1 Time of day: Broadly speaking, the consensus among the reviewed papers

    in terms of peak time of day for PRN administration is mid-afternoon to night-time. This has been explained in terms of night-time insomnia and anxiety, and disturbed sleep as a feature of mental disorders (Usher et al, 2001; Stein-Parbury et al, 2008; Craven et al, 1987; Winterfield et al, 2009) lower staffing levels, either because fewer staff work on the night shift or because staff are busy and unavailable due to shift handovers (Curtis et al, 2007; Baker et al, 2010; Winterfield et al, 2009), ‘sundowning’ in elderly patients with dementia (Baker et al, 2010), and noncompliance with bedtime rules in child and adolescent patients (Winterfield et al, 2009). Peak times were also observed in the mornings by Evans & Di Scipio (1980) and Curtis & Kapp (2003), who ascribe it to the relative non-availability of staff because this is a busy time, or

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    because of anxiety brought about by the doctors’ appointments which were held at this time.

    2.7.2 Day of week: Variations in PRN administration throughout the week have

    also been observed, with peaks being reported on Monday, Tuesday, Thursday, Friday and at the weekends, and troughs being reported on Monday, Friday, and weekends. Possible reasons for observed peaks (where they are made) include anxiety about the outcomes of magistrates cases (held on Thursdays) (Usher et al, 2001), and fewer staff on duty meaning that PRN medication is relied upon more, and possibly more admissions (Fishel et al, 2004). The trough in PRN use that Fishel et al (2004) also report is consistent with their hypothesis that possible increases in admissions over the weekend result in more PRN use, because most PRN was found to be administered very early in the admission. However, troughs were also observed on Fridays and at weekends in Smith et al (2008) and Usher et al (2001). Usher et al propose that the weekend trough might be because there are fewer visits by relatives and appearances by consultants (both of which might provoke anxiety), and because staff are less busy and therefore have more time to spend therapeutically with patients.

    2.7.3 Month: Finally, an interesting aspect of temporal distribution of PRN use is

    reported by Vitiello et al (1987) who found a significant difference in the distribution of PRN medication throughout the year, with the maximum being in March, and the minimum in December. As this was a study of a child psychiatric unit, the trough in December was attributed to the possible influence of Christmas, which may make patients more compliant or staff more tolerant towards disruptive behaviour.

    2.8 Antecedents of PRN use Several difficulties appear when attempting to discover the antecedents of PRN use. Firstly, antecedents frequently go unreported when PRN is administered. While this is an interesting finding in itself, it means that there is uncertainty about the true prevalence of the different antecedents which are reported. Secondly, there is usually a lack of precision about the definitions of the antecedents, and indeed, apparently similar verbal labels can be given to different antecedents. For example, Curtis & Capp (2003) report agitation and restlessness as different antecedents, but as they are not specifically defined, it is hard to tell how they were differentiated in practice. Agitation and restlessness are also reported in Usher et al (2001) and again, they are not differentiated. Mason & Dewolfe (1978) report agitation and overactivity. Studies also use combined categories of antecedents, making comparison across studies even more problematic. Philip et al (2008) use a category they call ‘agitation/anxiety’, as well as agitation and anxiety as separate antecedents. Dean et al (2009) have a combined category ‘insomnia/agitation’, as well as agitation and insomnia. Curtis et al (2007) combine this problem with that of possible duplication and redundancy mentioned previously with their categories of ‘agitation/anger/aggression’, ‘elevated/ upset/anxious’ and ‘irritable/unsettled/ restless’. Vitiello et al (1987) refer to ‘disruption on the ward’, a combination of fighting and unco-operativeness. Another problem is a lack of detail in reporting. Three studies report patients requesting PRN medication as the antecedent for its administration, and one of them also reports PRN medication being administered at the doctor’s instruction, but the complaint for which PRN medication is requested is not noted. Two of these studies are retrospective casenote audits, and this lack of detail is an example of one of the problems with this methodology. Finally, because there is usually no rating of the severity of the behaviour or symptom for which PRN medication is administered, it is

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    uncertain how appropriate the intervention might have been. The one exception to this among the studies reviewed is Chaichan (2008), who reports on the use of the Excited Component of the Positive and Negative Symptom Scale (PANSS-EC) as a criterion for the administration of PRN medication to agitated patients. Overall, there was no significant difference in mean number of doses of PRN medication for agitation between the patients who were screened on admission with PANSS-EC and those who were not, but significantly more PRN medication was administered in the first three days of their admission to those who had been screened, who also had significantly fewer episodes of aggression during their inpatient stay. While Chaichan cautions that these findings require further testing, it was concluded that screening led to a more favourable clinical outcome. Lack of reporting of significance levels for observed differences between different antecedents and between the same antecedents at different study sites, or before and after interventions is a more general problem that was encountered in the review, and must be added to the more specific problems discussed above. Lack of reporting antecedents of PRN administration was noted in 11 of the papers reviewed. The rates for non-reporting of antecedents range from one percent (O'Reilly & Rusnak, 1990) to 43% (Curtis et al, 2007), with a median reported value of 14% (O'Brien, & Cole, 2004). See Table 1 for a summary of this finding in the studies reviewed. The most commonly reported antecedent for PRN administration was agitation, being mentioned in 21 of the studies reviewed. This was followed by insomnia, reported as an antecedent of PRN administration in 11 studies. Agitation and insomnia also feature in compound classifications of reasons for PRN administration in some studies (i.e. agitation/anger/aggression, agitation/anxiety, and insomnia/agitation). Agitation was also the most frequently reported indication for PRN medication, accounting for an average of 49.16% of PRN administrations across the 21 studies reporting it, while insomnia accounted for an average of 22.4% of PRN administrations across the 11 studies which report it. Verbal and physical aggression and deliberate self-harm were comparatively rarely reported as antecedents of PRN use. PRN was reported as used to prevent likely physical aggression in four studies (accounting for an average of 27.13% of PRN administered in them), to contain actual physical aggression in five studies (accounting for an average of 13.62% of PRN administered in them), to contain verbal aggression in two studies (accounting for an average of 10.75% of PRN administered in them), and in response to deliberate self-harm in two studies (accounting for 6% of PRN administered in them. Similarly, PRN medication was rarely reported as being administered to alleviate psychiatric symptoms. Psychotic symptoms and anxiety were each reported as antecedents of PRN administration in four studies (with psychotic symptoms accounting for 9.33% of PRN administration and anxiety accounting for 10.28%), and panic was cited as an antecedent in one study (accounting for one percent of PRN administered). Antecedents mentioned in the studies reviewed and the proportion of PRN administrations that they account for are presented below in Table 3.

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    Table 3. Antecedents and non-reporting of anteceden ts in studies reviewed.

    Antecedent Study/studies % of PRN

    administrations Average

    % Antecedents.not reported Mason & Dewolfe (1974)

    O’Reilly & Rusnak (1994) Fishel et al (1994)

    Craven et al (1997) Usher et al (2001) Geffen et al (2002)

    Curtis & Capp (2003) O’Brien & Cole (2004)

    Dean et al (2006) Curtis et al (2007)

    Stein-Parbury et al (2008)

    11% 1%

    13% 9%

    36.6% 41% 9%

    14% 32.3% 43%

    36.8%

    18.7%

    Agitation Mason & Dewolfe (1974)

    O’Reilly & Rusnak (1990) Fishel et al (1994)

    Craig & Bracken (1995) Craig & Bracken (1995)

    Gray et al (1996) Kaplan & Busner (1997) Kaplan & Busner (1997) Kaplan & Busner (1997)

    Geffen et al (2002) Curtis & Capp (2003) O’Brien & Cole (2004)

    Dean et al (2006) Baker et al (2008)

    Stein-Parbury et al (2008) Philip et al (2008) Smith et al (2008) Dean et al (2009) Dean et al (2009) Baker et al (2010)

    64% 4%

    38% 61%1 57%2 11.9% 100%3 93%4 91%5 49% 19% 23%

    38.7% 71.5% 17.9% 75% 60%

    38.7%6 29.6%7

    77%

    51%

    Verbal aggression McLaren et al (1990) Stein-Parbury et al (2008)

    9% 12.5%

    10.75%

    Psychotic symptoms Geffen et al (2002) Curtis & Capp (2003)

    Curtis et al (2007) Smith et al (2008)

    15% 10% 12% 0.3%

    9.33%

    Insomnia O’Reilly & Rusnak (1990) Fishel et al (1994) Geffen et al (2002)

    Curtis & Capp (2003) Curtis et al (2007)

    89% 33% 17% 10% 10%

    1 Intermittent PRN patients. 2 Discrete PRN patients. 3 Combined PRN and stat doses in a private hospital. 4 Combined PRN and stat doses in a state hospital. 5 Combined stat and PRN doses in a county-university hospital. 6 Baseline figure 7 Post-intervention figure.

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    Philip et al (2008) Smith et al (2008)

    Goedhard et al (2007) Goedhard et al (2007)

    Dean et al (2009)

    9% 7%

    17.3%8 13.7%9 15.5%

    22.15%

    Anxiety O’Reilly & Rusnak (1990) Philip et al (2008) Smith et al (2008)

    4% 8%

    16%

    9.33%

    Panic O’Reilly & Rusnak (1990) 1% 1% Likely physical aggression McLaren et al (1990)

    Craig & Bracken (1995) Swart et al (2011)

    25% 10%

    63.5%

    32.83%

    Overactivity Mason & Dewolfe (1978) 45% 45% Disruption on the ward Vitiello et al (1987) 70% 70% Physical aggression McLaren et al (1990)

    Craig & Bracken (1995) Dean et al (2006) Dean et al (2009) Dean et al (2009)

    24% < 10% 14.5% 14%10 5.6%11

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    that nurses were significantly more likely than doctors to consider that hallucinations and delusions, formal thought disorder, and suicidal ideation were appropriate indications for PRN use, although there was close agreement between doctors and nurses concerning anxiety and conflict with co-patients as appropriate indications. Doctors were more likely than nurses (although significance levels are not reported) to view dysphoria/distress and sleep disturbance as appropriate indications. Regarding PRN anticholinergics, nurses were significantly more likely to select inappropriate indications. Doctors were significantly more likely than nurses to view agitation and sleep disturbance as indications for the administration of PRN benzodiazepines, and there were high levels of agreement between doctors and nurses concerning the appropriateness of anxiety, agitation, and sleep disturbance as appropriate indications for their use. These qualitative findings largely confirm the antecedents of PRN use identified in the empirical studies, although as we have seen in the discussion of clinical decision-making in the administration of PRN medication above, factors other than patients’ symptoms and behaviour which are linked to individual staff characteristics, staffing levels, and the level of psychopathology exhibited by other patients on the ward also influence PRN use. As part of a wider study of medication refusal by patients, Baker et al (2009) examined the antecedents of two other aspects of PRN use: PRN refusal and demanding PRN medication. This study is the only one of those surveyed which mentions these. Refusing PRN medication was found to be related to resistance to staff demands in other areas, and the ward door being locked. PRN refusal also had the strongest relationship to overt aggression, and was also associated with drug use and absconding. It also appeared to be associated with more severe containment methods. Demanding PRN medication was strongly related to passive resistance behaviours (such as refusing to eat, refusing to sleep, refusing to see healthcare staff and refusing to get out of bed), to the ward door being locked, nurse staffing levels, ancillary community teams, and the use of special observations. There were additional relationships with drug/alcohol use, and stronger relationships with absconding and aggression. While this was a large, multi-centre study, its cross-sectional design means that the direction of causality cannot be determined, and so the variables associated with refusing or demanding PRN medication might not be antecedents, but rather consequences. The statistical modelling strategy used may also identify some variables as significant purely by chance. Many patient factors (such as insight, and knowledge of and understanding about medication) which might bear on medication refusal were not measured. The study was only able to measure diagnosis as a dichotomous variable (e.g. suffering from schizophrenia or not), while a more detailed approach might have revealed further associations with medication refusal. 2.9 Outcomes of PRN use Fifteen of the studies reviewed reported on the effectiveness of PRN medication, 14 of which were ward-based, empirical studies. As with the antecedents of PRN administration, eight of the empirical studies noted a lack of reporting of outcomes (Fishel et al, 1994; Craig & Backen, 1995; Usher et al, 2001; Geffen et al, 2002; Curtis & Capp, 2003; Curtis et al, 2007; Smith et al, 2008; Stein-Parbury et al, 2008). Between 2% and 64% of PRN administrations were reported as not recording outcomes, with a mean rate of approximately 38.13% (this is an approximate figure because one value was reported as “nearly half”). Seven studies (Craig & Backen, 1995; Usher et al, 2001; Geffen et al, 2002; Curtis & Capp, 2003; Stein-Parbury et al, 2008; Curtis et al, 2007) reported that PRN medication had been ‘effective’, but give no operational definition of effectiveness. These studies report effectiveness rates of between 5% and 76%, with a mean of 44.13%. Nine studies (Vitiello et al,1987;

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    Fishel et al, 1994; Craig & Backen, 1995; Usher et al, 2001; Geffen et al, 2002; Curtis & Capp, 2003; Curtis et al, 2007; Smith et al, 2008; Stein-Parbury et al, 2008) also reported the proportion of PRN administrations which had been considered ineffective. These range from 3.7% to 25%, with a mean of 18.73%. Six of the studies reviewed used operational definitions of PRN effectiveness. Vitiello et al defined effectiveness as symptom improvement within 90 minutes of administration, and report that 32% of PRN administrations achieved this standard. McLaren et al’s (1990) definition was that patients were ‘settled’ by nurses within an hour of receiving PRN medication, and that significant reductions in conflict behaviours within 30 minutes were observed in incidents where PRN use was precipitated by agitation, verbal abuse, and threatened or actual violence. However, just over a quarter of PRN administrations were not effective by this criterion. Walker (1991) defined effectiveness as symptom relief within two to three hours of administration, and reported an effectiveness rate of 45%, with anxiolytics being significantly more likely to be judged effective than antipsychotics. Fishel et al reported ‘favourable’ results (i.e. notes stated that the patient was “calmed”, or that “good results” or “improved sleep” were observed following PRN use) in 64% of PRN doses administered in the state hospital and 30% at the medical centre sites that were studied, and Smith et al (2008) report that 90% of unscheduled medication doses (i.e. PRN and stat doses) relieved the symptoms which they were administered to treat. Swart et al (2011) found that chlorpromazine and lorazepam were significantly more likely to take longer more than 30 minutes to produce settling effects, while olanzapine was more likely to produce settling effects in less than 30 minutes. In a qualitative study of clinicians’ knowledge and beliefs concerning PRN medication for psychoses, Geffen et al found that most of the participating clinicians used subjective and/or objective assessments of the effectiveness of PRN medication. Over 80% of their participants supported the effectiveness of PRN conventional antipsychotics for either agitation or psychotic symptoms, of which chlorpromazine was more likely to be selected as effective. PRN benzodiazepines were also regarded as effective for agitation, but less so for psychotic symptoms, and clonazepam and diazepam were the most likely to be selected as effective. However, 60% of nurses and 30% of doctors preferred to use PRN antipsychotics for agitation, despite evidence suggesting that benzodiazepines represent a relatively safe and effective treatment in acute settings. With regard to the preference for PRN conventional antipsychotics for the treatment of psychotic symptoms, Geffen et al comment that the short-term response of psychotic symptoms to PRN benzodiazepines is equivalent to that of PRN antipsychotics, but are safer, better tolerated, and avoid problems related to psychiatric polypharmacy. Similarly, Usher et al argue that the contemporary literature supports benzodiazepines, as the first choice of PRN for agitation and psychotic distress, and describe the high reliance upon conventional antipsychotics that they found as due to the lack of sedating effect in unconventional antipsychotics. An interesting perspective on the effectiveness of PRN medication is given in Evans & Di Scipio (1980), who estimated that approximately 70% of PRN doses administered to resistant, agitated adolescent inpatients took effect either immediately or within a few minutes of administration, which suggests that non-pharmacological factors exert a placebo effect. The administration of PRN medication under these circumstances is described as a ritualised “termination strategy”, representing an acceptable way of terminating a stalemated power struggle that protected both the nurse-patient relationship and the social unit of the ward. Thought-provoking as this finding is, it is based on retrospective analysis and is therefore prone to recall biases. Similarly, McLaren et al (1990) report that 7% of the episodes in which PRN was administered appeared to resolve in less than five minutes. This suggests that, since a specific medication effect could not have occurred in that time, this was due to either a placebo effect or a cathartic release of

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    tension during the behavioural crisis, or that the attention of nursing staff enabled the crisis to be contained. However, McLaren et al also comment that in most cases where PRN had been judged effective, a genuine pharmacological response had taken effect. The effectiveness or otherwise of PRN medication is not the only possible outcome of its use. There is also the risk of unwanted side effects and harmful consequences. As discussed above with regard to the relationship of PRN and regular medication, Geffen et al (2002) found that both receipt of PRN medication and greater frequency of PRN administration were significantly associated with morbidity, which was also significantly associated with the receipt of both PRN antipsychotics and benzodiazepines. This echoes Walker’s (1991) earlier finding that the 4% of patients who had documented side-effects after receiving PRN medication were all also receiving regular psychotropics. McLaren et al (1990) report that while significant reductions in conflict behaviours occurred within 30 minutes of receiving PRN medication, sedative effects were also significantly increased. Sleepiness was also reported as an unwanted side-effect by Vitiello et al (1987), which occurred in just over 5% of PRN administration, while acute dystonia occurred in just 0.24%. However, this might be an underestimate of the true prevalence of side-effects, as Geffen et al found that no doctors and only 4% of nurses among their participants specifically included an assessment of possible side effects when describing their assessment of the effectiveness of PRN medication. Another potentially harmful outcome of PRN use highlighted in the literature is the risk of falling. Aisen & Deluca (1992) found that falls among geropsychiatric patients who had suffered falls had received significantly more frequent PRN doses of benzodiazepines than patients who had not fallen. Patients who had fallen were also found to have received more frequent doses of neuroleptics, although this finding was only marginally significant. 2.10 Relationship of PRN use to other containment m ethods PRN medication is only one of a range of methods that can be used to contain disruptive and dangerous behaviour. It is not necessarily the first or only containment strategy to be used, and the principle of using the least restrictive containment method necessary is well established in clinical practice. McLaren et al (1990) found that 12% of PRN administrations on a medium secure unit were associated with manual restraint, and that in most incidents, PRN was administered after other interventions had been attempted, including talking with the patient (74%), attempting to distract the patient (35%), sending the patient to his/her room (29%), ignoring the patient’s behaviour (19%), and relaxation (7%). Curtis et al (2007) also found a range of interventions that had been attempted before administering PRN medication for 25% of incidents where PRN medication was used. These included talking with or counselling the patient (17%), distraction (5%), seclusion or time-out (4%), giving practical assistance (1%), and observation and review by a doctor (1%). Just over 2% of patients who received PRN medication were transferred to a locked, high-security observation unit. Therapeutic interventions in addition to PRN were more likely to be applied if the rationale for administering PRN related to psychotic symptoms, agitated/angry/aggressive behaviour, elevated/upset/angry behaviour, and sleep. Swart et al (2011) report similar results to Curtis et al in their study of PRN use in a child and adolescent inpatient unit, with other therapeutic interventions being attempted in just over a quarter of incidents where PRN medication was administered, including talking with/counselling the patient (17.2%), distraction (4.5%), seclusion or time-out (4.1%), practical assistance (0.8%), observation (0.4%) and review by a doctor (0.4%). The fact that other interventions were apparently not

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    attempted in around three-quarters of the incidents reported by Curtis at al and Swart et al suggests that PRN medication could be the primary intervention within inpatient care. However, it could easily be the case that other interventions are simply not documented as frequently as they occur, especially given the fact that ward environments are typically very busy, and that the accountability associated with administering medication (and seclusion and manual restraint) need not necessarily apply to other therapeutic interventions. It is not necessarily mandatory to document ‘talking’ interventions, and reporting might be incomplete where documentation is mandatory. As we have seen, it is common for key information (such as the reason for PRN administration and its effects) not to be recorded when PRN administrations are documented. Nurses might also underestimate the therapeutic value of what they might regard as quite unremarkable interactions with patients. This lack of reporting of other interventions is suggested in Swart et al’s finding that other therapeutic interventions were more likely to be documented when a rationale for the administration of PRN is recorded, which is similar to Curtis et al’s finding that other interventions were more likely to be applied (or rather, documented) when PRN is used to contain symptoms and quite disturbed behaviour. 2.11 Alternatives to PRN and their use. While pharmacological interventions are a cornerstone of inpatient psychiatric treatment and PRN medication is an important part of this, its use is not without criticism. Curtis et al (2007) comment that allowing or encouraging mental health nurses to rely upon PRN medication as the main containment strategy does them a disservice, and that their skillbase should be expanded in both undergraduate and in-service training. Thapa et al (2003) argue that PRN use can expose patients to unnecessary psychotropic medications. Evans & Di Scipio (1980) criticise reliance on PRN medication because it reduces attempts to use other management strategies that have the potential for teaching self-regulation and control. Donat (2005) echoes this, arguing that relying on the sedative effect of psychotropic medication can make it less likely that patients will develop the daily living and coping skills needed to function outside of inpatient settings, and that PRN benzodiazepines are contraindicated for a large proportion of psychiatric inpatients who have a history of comorbid alcohol and drug misuse. Furthermore, the unnecessary reliance upon PRN medication (along with seclusion and restraint) for behaviour management has been a primary focus of human rights litigation. Other concerns around perceived abuse or unethical use of PRN include its potential for being used to quieten patients, rather than taking the time to explore behaviour therapeutically (Usher et al, 2009). 2.11.1 Regular medication as an alternative to PRN medication: The need for

    PRN medication could arguably be reduced by changing clinical practice around regular medication. Mason & Dewolfe (1974) found that: 62% of patients prescribed PRN antipsychotics were receiving regular antipsychotic medication at a dose below what was rated as a conservative high-dose level. Increasing the dosages of regular medication might therefore reduce the need for PRN medication, and this strategy is mentione