Withdrawal syndrome

Unpleasant mental and physical symptoms experienced when a person stops using a drug on which he or she is dependent (see drug dependence). Withdrawal syndrome most commonly occurs in those with alcohol dependence or dependence on opioids, in smokers, and in people addicted to tranquillizers, amfetamines, cocaine, marijuana, and caffeine. Alcohol withdrawal symptoms start 6–8 hours after cessation of intake and may last up to 7 days. They include trembling of the hands, nausea, vomiting, sweating, cramps, anxiety, and, sometimes, seizures. (See also confusion, delirium tremens, and hallucinations.) Opioid withdrawal symptoms start after 8–12 hours and may last for 7–10 days. Symptoms include restlessness, sweating, runny eyes and nose, yawning, diarrhoea, vomiting, abdominal cramps, dilated pupils, loss of appetite, irritability, weakness, tremor, and depression. Withdrawal symptoms from barbiturate drugs and meprobamate start after 12–24 hours, beginning with tremor, anxiety, restlessness, and weakness, sometimes followed by delirium, hallucinations, and, occasionally, seizures. A period of prolonged sleep occurs 3–8 days after onset. Withdrawal from benzodiazepine drugs may begin much more slowly and can be life-threatening. Withdrawal symptoms from nicotine develop gradually over 24–48 hours and include irritability, concentration problems, frustration, headaches, and anxiety. Discontinuation of cocaine or amfetamines results in extreme tiredness, lethargy, and dizziness. Cocaine withdrawal may also lead to tremor, severe depression, and sweating. Withdrawal symptoms from marijuana include tremor, nausea, vomiting, diarrhoea, sweating, irritability, and sleep problems. Caffeine withdrawal may lead to tiredness, headaches, and irritability. Severe withdrawal syndromes require medical treatment. Symptoms may be suppressed by giving the patient small quantities of the drug he or she had been taking. More commonly, a substitute drug is given, such as methadone for opioid drugs or diazepam for alcohol. The dose of the drug is then gradually reduced.