Drug Abuse:
– Defined as the non-medical use of any drug (usually psycho-active) that is unacceptable by the society and whose use could result in health problems. Drug Dependence: – Individuals become dependent on drugs due to the development of the following: Psychological dependence: – Severe compulsion and craving to take the drug repeatedly to re-experience a pleasant feeling e.g. euphoria. Physical dependence: – The body becomes adapted to the drug resulting in the necessity to continue its use to avoid a physical withdrawal syndrome occurring on drug withdrawal. Tolerance: – Decreased response to a drug to its continuous administration such that a larger dose of the drug is required to produce the same initial effect resulting in loss of control of the addict over amount of drug used.
Classification of Drugs of Abuse
CNS depressants:
Sedative-hypnotics: –
Barbiturates,
Benzodiazepines,
Alcohol. Narcotics: –
Morphine, Heroin,
Codeine, Pthidine.
CNS stimulants:
Caffeine, Nicotine,
Cocaine, Amphetamine, Khat. Hallucinogens: Lysergic acid diethylamide (LSD). Cannabis: Hashish, Marijuana, Bhang. Inhalants: – Induce euphoria and hallucinations: Solvents in glues and paints (Strong dependence). Anaesthetics e.g. Nitrous oxide and Ether (moderate dependence) N.B: – Drug abuse occurs more with shorter acting agents and withdrawal syndrome is more severe than that following longer acting agents. Barbiturates (Strong) and Benzodiazepine (Moderate) dependence Acute effects: – Euphoria, relieve anxiety and insomnia. Risk of chronic abuse: Anterograde and Retrograde memory loss. Withdrawal syndrome: – severe with Barbiturates and mild with Benzodiazepines. Insomnia, anxiety, tremors, delirium, hallucinations and convulsions. Management of Barbiturates and Benzodiazepine abuse is by replacement of short acting agent with longer acting agents which produce less severe withdrawal syndrome. e.g. Phenobarbital for Pentobarbital, Diazepam for Alprazolam and Triazolam. Alcohol dependence (Strong dependence) Acute effects: – Euphoria, Relaxation, Increased self-confidence. Risk of chronic abuse (Alcoholism): Withdrawn, homicidal or suicidal individual. Work and family problems. Black outs (loss of memory for a certain period) and Dementia. Organ damage e.g. liver cirrhosis, peptic ulcer, thiamine deficiency. Withdrawal syndrome: – Insomnia, anxiety, tremors, delirium, hallucinations and convulsions, Delirium tremens (Delirium, tremors, psychosis and visual hallucinations of crawling bugs). Management of Alcohol abuse: Replacement of Alcohol with Diazepam; it is longer acting and withdrawal from it is less severe. Thiamine supplements. Treatment of convulsions (with Diazepam). Psychotherapy (Group therapy). Disulfiram: – Inhibits alcohol metabolism with accumulation of Acetaldehyde leading to nausea, vomiting and flushing (Disulfiram reaction). To avoid this reaction, patients eventually give up their drinking. Opioid dependence (Very strong dependence) Acute effects: – Euphoria – Apathy (Drowsiness and Hypo-activity). Risk of chronic abuse: Fatal overdose (Homicide, suicide or accidents). Infections from syringes (Hepatitis, AIDS). Withdrawal syndrome (Associated with increased sympathetic activity): Craving for the drug, anxiety, insomnia, tremors. Pilo-erection, mydriasis, tachycardia, hypertension, hot and cold flushes. Abdominal cramps, vomiting, diarrhea, rhinorrhea, lacrimation. Management of Opioid abuse: Replacement of Morphine or Heroin with Methadone. Then Methadone is gradually withdrawn. Methadone is longer acting agent and withdrawal from it is less severe. Clonidine is given to reduce the sympathetic discharge. Naltrexone is given to block the Opioid receptors resulting in loss of the euphoric effects of Opioids and loss of the desire to take the drug. Symptomatic treatment during the withdrawal syndrome (Anxiolytics, Anti-emetics and Antispasmodics). Nicotine dependence (Very strong psychological dependence) Acute effects: – Euphoria, Decreased anxiety, Increased concentration. Risk of chronic abuse: – Cancer, Lung diseases, Ischemic heart disease. Withdrawal syndrome: – Insomnia, Anxiety, Increased appetite, Decreased concentration, Headache, Aggression. Management of Nicotine dependence: Psychotherapy (group therapy). Nicotine replacement by Nicotine gum or Transdermal Nicotine patch. Clonidine to suppress the sympathetic activity. Cocaine dependence (Very strong dependence) Acute effects: Increased Alertness, Insomnia, Decreased fatigue. Euphoria: – The intensity of euphoria depends on the route of administration. I.V route produces Intense euphoria (i.e. The Rush): – Risk of infections from syringe. Intranasal route produces less intense euphoria (i.e. High): – Risk of nasal septal perforation. Smoking produces Intense euphoria: – No risk of infection from syringes. Risk of Cocaine abuse: – Risk during the acute administration of Cocaine (i.e. The Run). Cocaine has short duration of action (1.5 hours) therefore patients administer the drug every 15 minutes to get the Rush or to avoid withdrawal symptoms until the patients become exhausted. Overdose toxicity: – Occurs during the Run (due to increased catecholamines): Convulsions. Arrhythmias, Hypertension and Myocardial infarction. Cerebral accidents. Risk of chronic Cocaine abuse: – Psychosis with hallucinations and Delusions. Withdrawal syndrome: – Fatigue, Sleep, Depression and over-eating. Treatment: – Antidepressants and Antipsychotics. Amphetamine dependence (Strong dependence) Amphetamine dependence is similar to Cocaine dependence but Amphetamine is: Longer acting. Less addictive. More psychotic. Lysergic acid diethylamide (LSD) dependence. Tolerance develops quickly, so the drug is taken as a recreational drug and not on a regular basis resulting in No dependence. Acute effects: Euphoria. Sensory changes (Sights and Sounds appear distorted and fantastic). Sounds are perceived as colors and colors as sounds. Hallucinations, Delusions, Illusions, Philosophical and Creative thinking. Risks of LSD abuse: Bad trips: – Frightening hallucinations resulting in homicide or suicide. Flash backs: – The patient re-experiences the frightening hallucinations months after stopping the drug. Psychosis: – Precipitates Psychosis in borderline psychosis even after a single dose. Management of LSD abuse: Calm the patient during the bad trips. Benzodiazepines. Antipsychotics.