Over half of the patients admitted with self-poisoning will have some problem of drug or alcohol abuse or dependence. At least 10% will undergo a clinically significant withdrawal reaction. Withdrawal following a drug overdose is more likely to be severe than an elective detoxification for a number of reasons:

• Intercurrent medical illness (aspiration pneumonia etc)
• Coexistent psychiatric illness
• Ingested drugs contributing to symptoms (e.g. delirium)
• Abrupt cessation of drugs
• Shorter half lives of drugs due to GI decontamination
• Late recognition/treatment of the withdrawal syndrome

An accurate as possible history, to identify patients at risk of withdrawal, and close monitoring, to identify the problem early, followed by appropriate specific treatment will minimise conflict and morbidity associated with drug and alcohol problems.

Alcohol withdrawal is the most common serious withdrawal syndrome. Benzodiazepine and opioid withdrawal syndromes can often be managed as an outpatient dependent on the home circumstances of the patient and any co-morbid psychiatric or medical conditions. Stimulant abuse is becoming much more of a problem with the increasing use of amphetamines and cocaine. Barbiturates cause a now rare but very serious withdrawal syndrome. Specialist help should generally be sought for this condition.