[Abuse of alcohol and benzodiazepine during substitution therapy in heroin addicts: a review of the literature].

INTRODUCTION

In spite of its seriousness, dependence on alcohol and benzodiazepines during substitution treatment are poorly documented. Its frequency is nonetheless significant. According to studies, between one and two thirds of patients are affected. This consumption is under verbalized by patients and underestimated by carers. In one study, where the average diazepam doses were from 40 to 45 mg per day, 30% of the patients were taking 70 to 300 mg per day, two thirds having experimented with a fixed dose of 100mg. Benzodiazepines, especially diazepam and flunitrazepam, were studied versus placebo. Thus, 10 to 20mg of diazepam gave rise to euphoria, a sensation of being drugged, sedation and lessening of cognitive performance. The aim of this consumption is to potentiate the euphoria induced by opioids, a "boost" effect during the hour after taking it, or the calming of the outward signs of withdrawal. The most sought after molecules are the most sedative, those with pronounced plasmatic peaks, and the most accessible.

LITERATURE FINDINGS

In multidependant subjects, opioid dependence had been earlier in adolescence, with a number of therapeutic failures. They had been faced with repetitive rejection and separation during childhood, medicolegal and social problems. Somatization, depression, anxiety and psychotic disorders are frequent in this subgroup. Heavy drinkers under methadone treatment are highly vulnerable to cocaine. Their behaviour is at risk, with exchange of syringes; their survival rate is 10 years less than that of moderate consumers of alcohol. Most are single, with a previous prison, psychiatric or addictive cursus and they present significant psychological vulnerability. For some authors, benzodiazepines indicate a psychiatric comorbidity. Methadone significantly reduces the consumption of alcohol by nonalcoholic heroin addicts. Although alcohol is an enzymatic inductor of methadone catabolism, with bell-shaped methadone plasma curves over 24 hours, a substitution treatment is recommended. It has a minimum impact on care, in spite of efficiency and retention in therapeutical programs, allowing the subject's inclusion in the framework of a more regular and sustained medical follow-up. Treatment of benzodiazepine dependence by a progressive regression of doses has little efficacy in subjects which cannot control how much medication they are taking. Certain authors have suggested maintenance treatments of clonezepam. The most appropriate therapeutic propositions are: (1) maintenance of therapeutic links though a framework of deliverance from flexible substitution treatment; (2) prevention by cautious prescribing and control of dispensing medication; (3) parallel treatment of psychiatric comorbidities and related personality disorders; (4) individual psychiatric treatment, either institutional or in consistent networks.