In contrast to the use of methadone as a stabilisation agent, there is little evidence in favour of prescribing benzodiazepines on a maintenance basis. Since temazepam capsules ('Jellies') ceased to become prescribable on the NHS, injecting misuse of benzodiazepines appears to have become less common. The street value of black market benzodiazepines is significantly less than that of heroin or cocaine, and illegally available benzodiazepines are all of pharmaceutical origin. The combination of these factors reduces the potential of substitute prescribing to minimise harm in terms of spread of blood-borne infectious diseases, acquisitive crime and use of illicitly manufactured drugs of unknown purity and content. The main arguments remaining for such prescribing are to engage patients in treatment and to reduce their contact with the drugusing/ dealing community.

The demographic profile of patients dependent solely on benzodiazepines is different to that of all other drug misusers. Such patients are likely to be older and are much more likely to be female than other drug misusers; typically, daily use of benzodiazepines is in the region of the equivalent of 10 to 30mg of diazepam. The origin of dependency is often iatrogenic, and ongoing management frequently takes place in a primary care setting. As such, this group presents a very different challenge for management. Nevertheless the principles of good management as described above should be adhered to, including clear diagnosis of dependence, formulation of clear treatment goals and milestones, regular review and the use of methods to prevent diversion. Abstinence should be the preferred goal but may not be achievable in all cases. If a period of stabilisation prescribing is agreed then shorter-acting drugs such as temazepam or nitrazepam should be converted to the equivalent dose of the longer-acting chlordiazepoxide (this is preferred to diazepam due to its lower street value) (see appendix 7, page 123 for conversion table).

The other well-defined group of benzodiazepine misusers are those who use these drugs as part of a 'cocktail' of polydrug use. Up to 90% of attenders at drug misuse treatment centres reported use of benzodiazepines in a one-year period (Perera KM,Tulley M, Jenner FA, 1987), and the doses misused are often very high; diazepam 100mg daily is a typical amount consumed by a heavily dependent polydrug misuser.