[Two years follow-up of a heroin users cohort treated with high dosage buprenorphine. Results of the SPESUB study (pharmacoepidemiologic follow-up of general practice Subutex)].

BACKGROUND

Since February 1996, French GPs are allowed to prescribe high dosage buprenorphine for maintenance treatment of major opioid drug addiction. A prospective cohort of major opioid addicts was initiated in order to assess patient outcomes: follow-up, retention rate in treatment, drug use, intravenous injection and social situation evolution.

METHODS

Each GP, known to be involved in drug user management, had to include the first 10 opioid drug addict patients to whom he prescribed high dosage buprenorphine, with a maximum inclusion period of 3 months. Patients were followed up for two years and a regular standardized information was collected (usual data on drug users and prescription modalities).

RESULTS

Between May and July 1996, 919 patients (664 men and 255 women, mean age: 30 years) were included by 101 GPs. They had a long and serious history of drug addiction, important parallel consumption of cocaine, codeine and other illicit drugs and psychiatric problems (28% of definite problems and 45% of probable) and frequent hepatic conditions (hepatitis B: 23%, hepatitis C: 21%). Two years later, 55% of patients were still followed-up by the same GP and an additional 12% were followed by another GP or in a health care service (hospitalized or receiving methadone in a specialized centre). 13% were not followed, but GPs were able to describe their situation. 8% had been included by GPs who had dropped the study. Finally, 12% of patients were lost to follow-up. Among the 508 patients still followed-up by the same GP after 2 years, the substitution treatment rate was 84%. The dosage bracket had widened (inclusion: mean dosage=7.8 mg +/-4.5, minimum=0.8, maximum=28, median=8; after 2 years: mean=7.6 mg +/-5.4, minimum=0.4, maximum=28, median=8) and the duration of the prescription and dispensing had increased. Declaration of heroin intake in the previous month had fell from 40% to 11% and declaration of drug intake from 53% to 20%. Social situation had improved on average (housing conditions and work). There were 12 seroconversions for hepatitis B, 21 for hepatitis C and 4 for HIV. 14% of patients had declared intravenous injection of high dosage buprenorphine in the previous month.

CONCLUSIONS

After two years of follow-up, 55% of patients were still followed-up by the same GP and an additional 12% was followed by another GP or in a health care service. Among patients still followed up by the same GP, a reduction of drug related harm (seroconversions for hepatitis B, hepatitis C and HIV) was observed.