5.drugdependence

7/29/2019 5.DRUGDEPENDENCE

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Drug Dependence

Blanton, March 10, 2004


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Drug Abuse

Illicit designation varies with

culture

Illicit designation varies over

time

Licit US drugs currently include

caffeine, tobacco, and alcohol


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Drug Abuse

Signi f icant Morbidity and Mortal i ty

Economic Drain

Legal Drugs most commonly misused


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Drugs of Abuse

Trends of use and disuse

Trends of societal acceptance

and nonacceptance

Legalization/decriminalization

of marijuana- medical pot


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Terminology

Drug Abuse- use outside accepted norms

Compulsive use- preoccupation with drug

Psychological Dependence- need for drug to

maintain feeling of well being

Physical Dependence- changes that result inwithdrawal if drug is stopped

Tolerance- drug loses effectiveness


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Terminology

Addiction:

physical, psychological dependence,

tolerance

uncontrollable obsession to

obtain and use drug


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Classes of Drugs of Abuse

-Opioids

-CNS Depressants

-CNS Stimulants-Nicotine

-Cannabinoids

-Psychedelics

-Arylcyclohexylamines

-Inhalants


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Factors in Drug Abuse

Drug:

effects, availability, price

User:

heredity, psychiatric disorders,

risk-taking behaviorEnvironment:

social setting, peers


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Treatment of Drug Addiction

High Relapse Rate- CRAVING

Success---> Long term treatment

Supportive and/or Psych therapyAA and NA


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Tolerance

Dispositional- pharmacokinetic

Pharmacodynamic- functional

Behavioral- learned

Cross- similar class- substitute

Degree- dose, frequency, duration


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Physical Dependence

Not a single mechanism

Linked to Tolerance and Adaptation

Three Conditions:

-Sufficient Dose

-Sufficient Frequency-Sufficent Duration

Withdrawal in Absence of Drug


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Intensity of Withdrawal

Degree of Cellular Adaptation

Half-life of the drug


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Cross- Dependence

Clinical use of drugs from the

same class as the drug of

addiction- to reduce withdrawal:

methadone for heroinbenzodiazepines for ethanol


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Opiate Addiction

Significant # of health care

professionals

stress

easy access to pharmaceuticalgrade opiates


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Opiate Effects

intensely pleasurable feelings

IV Heroin

Rapid Tolerance- 100x doseincrease

Short t1/2

grade of heroin

Opiate Addiction


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Opiate Withdrawal- Signs

craving mydriasis

restlessness sweating

pain sensitivity goosefleshnausea vomiting

cramps diarrhea

muscle aches blood pressure

dysphoria yawning

insomnia fever


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Opiate Addiction Intervention

Methadone Substitution

titrated downward over

time

Clonidine for autonomicsymptoms


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Methadone: long half-life

High

Normal

Sick

Heroin

Methadone

0 6 12 18 24

Hours


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Acetylmethadol

Buprenorphine- partial agonist

Naltrexone- antagonist


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CNS Depressant Addiction

Cognition and Psychomotor

Performance

Overdosage--> Respiratory Arrest

Tolerance to Psychic and Motor

Effects, but not to respiratory

depression


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CNS Depressant Withdrawal

Must be treated

Risk of fatal status epilepticus

Ethanol and Barbiturates- more

dangerous than Benzodiazepines


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Concluding Remarks

Polysubstance Abuse

Underreporting of alcohol andnicotine use

Shame in admission of illicit

drug abuse


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Study Guide

1) Understand tolerance and

physical dependence.

2) Contrast opioid and CNS

depressant withdrawal symptoms.

3) Contrast medical managementof withdrawal from opioid and

CNS depressants.

5.drugdependence

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