Adverse effects can be caused by withdrawal of treatment with several classes of drug. Important among these are: alcohol, opiates, hypnotics, tranquillizers, antipsychotic drugs, antidepressant agents, anticholinergic preparations, sympathomimetic drugs, anticonvulsant drugs, corticosteroids, antihypertensive and antianginal drugs, and possibly drugs used to treat thrombosis. Neonates can suffer withdrawal symptoms from maternal drugs.Whenever abrupt drug withdrawal is contemplated, the risks and benefits should be carefully considered.