[Benzodiazepine withdrawal in subjects on opiate substitution treatment]

Benzodiazepines are the most widely used psychotropic agents in the world. Abuse and dependence are reported in the general population and among drug misusers, including those dependent on heroine. Benzodiazepine use by heroine users increases their risk of overdose, not only from heroin but also substitution drugs such as methadone and more recently buprenorphine. Hence, detoxification from benzodiazepines is desirable.

The objective of this paper was to review the literature and determine the best benzodiazepine detoxification procedure for opiate-dependent individuals receiving substitution treatment.

Relevant studies were sought through systematic searches of Medline and Toxibase (a database focusing on substance abuse).

There were fewer controlled studies than expected about benzodiazepine detoxification, and all of them excluded subjects who misused opiates or were in opiate substitution treatment. The best evidence supports a procedure where the patient is switched to a long-lasting benzodiazepine and the dose then tapered by 25% of the initial dose each week. Diazepam is the drug most often used in the framework. In opiate users, diazepam may raise special problems of misuse, as suggested by clinical and epidemiologic studies. Nonetheless, diazepam is the only benzodiazepine found to be effective for this withdrawal in controlled studies and some studies indicate that unprescribed diazepam use in heroin users is sometimes motivated by the desire to alleviate withdrawal symptoms and discomfort.

Although diazepam appears to have potential for abuse, the available data does not rule out its therapeutic interest for benzodiazepine withdrawal in patients on opiate substitution treatment in an adequate treatment setting. Specific studies of this population are needed.