Two years follow-up of heroin users treated by GPs with high dosage buprenorphine: the SPESUB study (pharmaco-epidemiological follow-up of high dosage buprenorphine in general practice)

Background: Since February 1996 French GPs are allowed to prescribe high do sage buprenorphine for maintenance treatment of major opioid drug addiction . A prospective cohort of major opioid addicts was initiated in order to as sess patient outcomes: follow-up, retention rate in treatment, drug use, in travenous injection and social situation evolution. Methods: Each GP, known to be involved in drug user management, had to incl ude the first 10 opioid drug addict patients to whom he prescribed high dos age buprenorphine, with a maximum inclusion period of 3 months. Patients we re followed up for two years and a regular standardized information was col lected (usual data on drug users and prescription modalities). Results: Between May and July 1996 919 patients (664 men and 255 women, mea n age: 30 years) were included by 101 GPs. They had a long and serious hist ory of drug addiction, important parallel consumption of cocaine, codeine a nd other illicit drugs and psychiatric problems (28% of definite problems a nd 45% of probable) and frequent hepatic conditions (hepatitis B: 23%, hepa titis C: 21%). Two years later, 55% of patients were still followed-up by t he 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 patient s were lost to follow-up. Among the 508 patients still followed-up by the s ame GP after 2 years, the substitution treatment rate was 84%. The dosage b racket had widened (inclusion: mean dosage = 7.8 mg +/-4.5, minimum = 0.8 m aximum = 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 dispensi ng had increased. Declaration of heroin intake in the previous month had fe ll from 40% to 11% and declaration of drug intake from 53% to 20%. Social s ituation had improved on average (housing conditions and work). There were 12 seroconversions for hepatitis B, 21 for hepatitis C and 4 for HIV. 14% o f patients had declared intravenous injection of high dosage buprenorphine in the previous month. Conclusion: After two years of follow-up, 55% of patients were still follow ed-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.