RT Journal Article SR Electronic T1 Unintentional rapid opioid detoxification JF Emergency Medicine Journal JO Emerg Med J FD BMJ Publishing Group Ltd and the British Association for Accident & Emergency Medicine SP 494 OP 495 DO 10.1136/emj.18.6.494 VO 18 IS 6 A1 M A Quigley A1 S H Boyce YR 2001 UL http://emj.bmj.com/content/18/6/494.abstract AB Naltrexone is a long acting opioid antagonist that is used in rehabilitation programmes to maintain heroin abstinence. It is a relatively new drug prescribed by specialists in substance misuse. Its actions and effects may not be familiar to many accident and emergency doctors or even to the people who take it. A case report is described where accidental ingestion of naltrexone results in a medical emergency by precipitating acute withdrawal in a heroin addict.