anti-depressants or what when dr bruce davies range tricyclics tetracyclics ssri snri maoi oddities...
TRANSCRIPT
Anti-depressants
Or What When
Dr Bruce Davies
Range
Tricyclics Tetracyclics SSRI SNRI MAOI Oddities Adjuvants
Factors Influencing Choice Features of illness, e.g.
agitation, hypersomia Suicide risk Other therapy Other illness. Side effects Cost Special problems e.g.
Age, driving, pregnancy
Drug Failure
Non compliance. Inadequate dosage. Other drugs e.g. alcohol, caffeine. Unresolved outside problems. Up to 25% failure even if above don’t
apply.
Tricyclics
Amitryptyline Potent sedative Weight gain ++ Anticholinergic ++ Most researched 150mg / day
(Therapeutic in 95% of adults)
Clomipramine Similar side effects to
amitryptyline. Said to be best for
obsessional symptoms. 150mg / day
Tricyclics
Dothiepin Sedative Same side effects as
amitryptyline. By far and away the
most toxic antidepressant.
150 mg / day
Imipramine Stimulant Anticholinergic ++ 150 mg/ day
Tricyclics
Lofepramine Least toxic TCA. Minimal sedative side
effects. Anticholinergic + Doubts about efficacy. 210 mg / day
Protriptyline Stimulant. Anticholinergic + 40mg / day
Tetracyclics
Maprotiline Similar side effect
profile to amitryptyline.
Seizures severe in overdose.
150 mg /day
Mianserin Good safety in
overdose. Few sedative or
anticholinergic properties.
? Agranulocytosis risk 90 mg / day
SSRI
First choice in elderly. First choice if heart
disease. First choice if suicide
risk. More expensive.
Side effects Like TCA reduce with
time. Gut problems
predominate. Flat dose response
curve – so no need to titrate dose upwards.
?
SSRI
Citalopram Few interactions
Most expensive
20 mg /day
Fluoxetine Sedation –
Skin s/e
Anxiety +
Cheapest
20-80 mg /day
Fluvoxamine Gut s/e + Insomnia - 200 mg /day
Paroxetine Sedation + Withdrawal problems ?
20 mg /day
Sertraline Diarrhoea 50 mg /day
SSNRI
Venlafaxine Selective Serotonin and noradrenaline
reuptake inhibitor – like amitryptyline. Few other effects – unlike amitryptyline. 75-150mg / day minimum Dry mouth, somnolence, high BP, nausea,
headache and dizziness.
MAOI
The old ones block peripheral MAOI ( B ) and central MAOI (A) so a low tyramine diet is needed. ? Obsolete.
Moclobemide. Only MAOI-A. ? Role. ? Special place in anxiety disorder. 300-600mg / day.
Oddities
Trazodone. Unique structure. Low cardiotoxicity, few anticholinergic
side effects. Drowsiness +. Nausea. 150 mg /day.
Oddities
Tryptophan Natural amino acid - Serotonin precursor. Eosinophilia-myalgia syndrome, Hospital
initiation only. Adjuvant to others ?Flupenthixol Some doubts as to efficacy. Fast action 1 mg / day
Adjuvants and Combinations
Realm of specialists Lithium,
carbamazepine Mixtures i.e. SSRI and
TCA Dangerous – need
expert supervision
Anxiety Usually worth trying a
antidepressant. May be useful to avoid the
stimulant ones ! May need higher doses. Initiation may lead to
paradoxical increase in symptoms. ? Cover with short course of anxiolytic.
Anxiety
? Role of benzodiazepines.
? Beta-blockers.
Buspirone. Some efficacy, but
small. Slow onset, 2-4 weeks.
DSM - IVDuration > 2 weeks
Depressed mood or Marked loss of interest or pleasure in normal activities
Plus 4 of:
i. Significant change in weight
ii. Significant change in sleep pattern
iii. Agitation or retardation
iv. Fatigue or loss of energy
v. Guilt / worthlessness
vi. Can’t concentrate or make decisions
vii. Thoughts of death or suicide
Incidence Of Depression : 2000 Patients
100 - major
100 - minor
200 - subclinical
Depression. In 50% of patients it may not be acknowledged.
ICD - 10Patient has low mood:
1) How bad is it and how long has it been going on?
2) Have you lost interest in things?
3) Are you more tired than usual?
If the answer is yes to these, then:
4) Have you lost confidence in yourself?
5) Do you feel guilty about things?
6) Concentration difficulties?
7) Sleeping problems?
8) Change in appetite or weight?
9) Do you feel that life is not worth living any more?
ICD - 10
Mild
Two criteria from 1-3 and 2 others. Moderate
Two criteria from 1-3 and 3-4 others or a yes to question 5.
Severe
Most of the criteria in severe form especially questions 5 & 9.
BUT BUT BUT
But there is a lot more than the drugs.
The use of other therapies is equally important.
The doctor may be the best drug.
Availability is often the limit to other treatment methods.
Based On
BNF June 2000. Depression in General Practice. Tylee,
Priest & Roberts. Pub. Martin Dunitz. 1996. GP Psychotropic Handbook. S Bazire.
Quay Books. 1995. Basic Notes in Psychiatry. Michael Levi.
Kluwer Books. 1997.