[Buprenorphine abuse: high dose intravenous administration of buprenorphine]

In France, actually, around 70 000 drug addicts are treated with buprenorphine available as sublingual tablets. Clinical studies have demonstrated the clinical efficacity of buprenorphine for opiate addiction. But, it has been reported that some of them injected buprenorphine. Some inquiries have suggested measured with 10% to 40% injectors. To use buprenorphine tablets for injections have had heavy sanitary consequences (4).

To know the use buprenorphine context in our population and to analyse the circumstances and outcomes of buprenorphine injection for drug addicts.

In 1998-1999, we conducted a cross-sectional survey using a structured questionnaire. Information wax collected during a 30-minute face-to-face interview through an 69-item structured questionnaire administered by trained investigators. The questionnaire was composed of questions about social demographic data, the drugs taken before the first use of buprenorphine, the circumstances of the first buprenorphine experiment, the reasons for the first buprenorphine injection into drug addicts, the other substances used in the same time, the risks behaviors, the sensations seeking, the medical consequences. The questionnaire was first tested in a pilot study through ten patients. Drug addicts were followed-up in 8 drug abuse treatment centres among which 2 networks of general practitioners in Paris region, in Strasbourg region and in Nice region. The investigators were general practitioners, psychologists, psychiatrists, educators, nurses. All drugs addict which reported use buprenorphine were seen in treatment centre and were 18 years old or older, were eligible. Drugs addict with severe mental disorders, unable to answer the questions were excluded. Respondents received an assurance of confidentiality and informed consent was obtained. Standard descriptive statistics were used to analyse subjects characteristics: frequency, standard deviation. The study was funded by the Observatoire Français des Drogues et des Toxicomanies (OFDT).

Of the 779 consecutive drug addicts interviewed, 770 completed the questionnaire. The study has shown that the majority of subjects were male (77.2%), mean age was 31.3 (SD: 5.98). Most of them were unmarried (67.5%). They had no real employment (56.5%). The mean age at the first use opiate was 19.5 (SD: 4.5). The mean age at the first heroin injection was 20.7 (SD: 4.6). At the time of interview, most of drugs addict used more than two types of drugs (42.6%). Many associations with buprenorphine are described particularly associations to alcohol (41.2%), benzodiazepines (40%), cocaine (12.4%), heroin (7.8%), crack (7.2%); most of these subjects getting buprenorphine without any medical prescription. Most drug addicts had asked themselves for using buprenorphine (61.0%). Near fifty per cent (49.5%) injected buprenorphine. Among them, 39.6% injected this substance the first time they used it. Curiosity (72.8%), need for injection (69.0%), sensation seeking (49.0%) were reasons given by drug addicts for buprenorphine injection. Others reasons were given: an inadequate dosage of sublingual buprenorphine, to find buprenorphine in black market. Buprenorphine injection took place in the secure environment (57.5%). Drug addicts were not alone when they injected (53.6%). The introducer was an buprenorphine user (57%). The first buprenorphine injection sensation was not pleasant (61%), although injection of buprenorphine is usually performed by 80% of them. However, 93% had been informed that buprenorphine injection was contra-indicated.

Since six years, many French patients have received a treatment for opiate addiction. High dosage buprenorphine is actually the principal treatment for substitution medication in France. Some misappropriations and wrong uses have been seen, the most frequent and sever being using tablets for injections. The prevalence of buprenorphine injection is high among drug addicts. The results of the study show that the first buprenorphine Injection takes places place a few time after the first buprenorphine use. The codependance to other substances is one of risk markers for intravenous use of buprenorphine tablets and the dangers of polyintoxication were known. Curiosity, need for injection favour buprenorphine injection. But, the sensation seeking brings on the drug addict too. The rather loose frame of prescription, a lack of training among general practitioners, the fragility of the specialises network, the complexities in the care of drug users which not resumed by a substitution must take into consideration. The drug addict's career, the subject's environment and the circumstances of the buprenorphine injection have not been previously described. However their knowledge are of prime necessity to prevent this abnormal use and to find the best treatment for drug addicts.