Phenazepam abuse in the UK: an emerging problem causing serious adverse health problems, including death

Phenazepam (fenazepam; 7-bromo-5-(2-chlorophenyl)-1,3-dihydro-2H-1,4-benzodiazepin-2-one; PNZ, 'Bonsai') is a benzodiazepine developed in the former Soviet Union during the 1970s to treat neurological disorders, epilepsy, and alcohol withdrawal syndrome. Its recreational use appears to have increased over recent years. Because of the lack of accessible data on this substance, it is important that information is made available to health professionals.

A literature search was conducted in relevant databases (Medline, Toxbase, PsychInfo, etc.), grey literature (using Google Scholar) and Internet sites to identify key data on phenazepam, including epidemiology such as availability, price, supply sources, confiscations, and health-related problems.

Information from these sources indicates the potential for serious adverse health consequences for this drug when taken recreationally and that its use is spreading in the USA and Europe. Although first use was reported in the UK in October 2009, major concerns in the UK arose in summer 2010 when individuals across Britain were admitted to hospital following overdose. Nine UK fatalities were reported in which phenazepam was detected in post mortem toxicology but not implicated in death. The first UK death directly involving phenazepam was notified in July and the second in November 2011.

This paper summarises the key information about phenazepam abuse and health problems of which health professionals, especially those in Emergency Departments, should be aware and presents new information in respect of fatalities caused by the drug.