Drug Abuse and Dependence

1. The term “drug abuse” is defined by the National Institute on Drug Abuse as: “the non-medical use of a substance for any of the following reasons – psychic effect, dependence, or suicide attempt/gesture”. The term “non-medical” generally refers to the use of prescription drugs in a manner inconsistent with accepted medical practice.

2. Important Terms and Concepts:

   1. self-administration – the end result of drug-seeking behavior; animal models

   2. tolerance – can be stated two ways: the effect of a specific dosage decreases with repeated administration, or a higher dosage is needed to produce the same effect with repeated administration.

1. mechanisms for the development of tolerance

1. dispositional tolerance – due to changes in the pharmacokineticproperties of the drug (absorption, distribution, metabolism and/or elimination)

2. pharmacodynamic tolerance – due to adaptive changes in the affected systems (e.g., down-regulation of receptors or compensatory physiological changes)

3. behavioral tolerance – an individual alters their behavior in order to adapt or compensate for the presence of drug

1. cross tolerance

3. dependence – should replace the term “addiction” because it is more useful in understanding the components of drug abuse

   1. physical dependence – is defined by the presence of a “withdrawal” or abstinence syndrome, which is characterized by signs and symptoms usually opposite to those produced by the acute administration of the drug.

   2. behavioral/psychological dependence – is the enduring problem with drug abuse and can occur independently of physical dependence.

   3. cross dependence

4. polydrug abuse – unlike drug abusers from previous generations, there are very few drug abusers who abuse only a single drug.

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3. Representative Classes of Drugs Capable of Producing Dependence:

   1. Cannabinoids: cannabis - a⁹-tetrahydrocannabinol, hashish

2. CNS Stimulants:

1. Amines

   1. d,l-amphetamine (Benzedrine)

   2. d-amphetamine (Dexedrine)

   3. diethylpropion (Tenuate)

   4. methamphetamine (Methadrine)

   5. methylphenidate (Ritalin)

   6. phenmetrazine (Preludin)

   7. phentermine (Ionamin)

2. Other

   1. caffeine

   2. cocaine

   3. ephedrine

3. Dissociative Anesthetics (psychotomimetics): ketamine (Ketaset, Ketalar), phencyclidine (PCP)

4. Hallucinogens:

   1. Tryptamines

      1. dimethyltryptamine (DMT)

      2. harmine

      3. lysergic acid (LSD)

      4. psilocin

      5. psilocybin

   2. Phenalkylamines

      1. methylenedioxyamphetamine (MDA)

      2. methylenedioxymethampehtamine (MDMA: Ecstasy)

   3. Phenethylamines

      1. dimethoxymethylamphetamine (DOM)

      2. mescaline (peyote)

   4. Anticholinergics

      1. atropine

      2. ditran

      3. scopolamine

5. Opioids

   1. Opiates

      1. codeine

      2. dihydrocodeine

      3. heroin

      4. hydrocodone (Vicodin, Dicodid, Hycodan)

      5. hydromorphone (Dilaudid)

      6. morphine

      7. oxycodone (Percodan, Percoset, Oxycontin)

      8. oxymorphone (Numorphan)

2. Synthetic Opioids

   1. alphaprodine (Nisentil)

   2. anileridine (Laritine)

   3. butorphanol (Stadol)

   4. levorphanol (Levo-Dromoran)

   5. meperidine (Demerol)

   6. methadone (Dolophin)

   7. methadyl acetate (acetylmethadol)

   8. nalbuphine (Nubain)

   9. pentazocine (Talwin)

6. Sedative-Hypnotics:

   1. Barbiturates

      1. amobarbital (Amytal)

      2. butabarbital (Butisol)

      3. pentobarbital (Nembutal)

      4. phenobarbital (Luminal)

      5. secobarbital (Seconal)

2. Benzodiazepines

• alprazolam (Xanax)

• chlordiazepoxide (Librium)

• clonazepam (Klonopin)

• clorazepate (Tranxene)

• diazepam (Valium)

• flunitrazepam (Rohypnol)

• flurazepam (Dalmane)

• lorazepam (Ativan)

• midazolam (Versed)

• oxazepam (Serax)

• temazepam (Restoril)

• triazolam (Halcion)
  

3. Other

   1. chloral hydrate

   2. ethinamate (Valmid)

   3. ethyl alcohol

   4. gammahydroxybutyrate (GHB)??

   5. glutethimide (Doriden)

   6. meprobamate (Miltown)

   7. paraldehyde

7. Volatile Intoxicants:

1. Anesthetics

1. ether

2. nitrous oxide

1. Solvents

   1. acetone and other ketones

   2. aliphatic acelates

   3. airplane glue, etc

   4. carbon tetrachloride

   5. freon propellants and other chlorinated and fluorinated hydrocarbons

   6. gasoline and other petroleum distillates

   7. paint thinner

   8. toluene

   9. trichloroethane

3. Other - amyl nitrate

8. Miscellaneous: nicotine

4. Therapies for Drug Dependence:

   1. Substitution Therapy – e.g., methadone

   2. Antagonist Therapy – e.g., naltrexone

   3. Contingency Therapy – e.g., disulfram

Category: Pharmacology Notes