Aim: There is a lack of longitudinal studies of buprenorphine dependence, an important opioid dependence in several countries. We investigated the course and outcome of buprenorphine dependence in an Indian clinic-attending cohort.
Design: Retrospective longitudinal study.
Setting: An addiction clinic in northern India.
Participants: Ninety-four male patients with buprenorphine dependence, registered for treatment between 1987 and 1993. Follow-up analyses were conducted for the 52 patients (55% of the index cohort) who completed more than a year of follow-up. In 48% of these 52 patients data were obtained from their clinical records of follow-up, while 52% were contacted specifically to obtain the required data on follow up.
Measurement: Baseline demographic and clinical variables; time spent in various phases of use or abstinence; outcome at the latest follow up; transition to other drugs during follow-up period.
Findings: Over an average follow-up duration of 3 years, 56% of the time was spent in dependent use, 12% in non-dependent use and 32% in abstinence. By the end of follow-up, 6% of patients were dead (annual death rate 1.9%), 33% were unchanged and 61% were classified as "improved". The proportion of patients with "improved" outcome increased over the years. Patients with poor outcome had shorter follow-up and hospital stay, and had used pentazocine and/or antihistaminic injections in the buprenorphine "cocktail" more often than those with better outcome. Thirty-two patients shifted to other drugs over the years, notably heroin or polydrug use. These "transition" patients had a family history of drug use more often, started their drug career earlier, had marital and legal complications more often, spent more time in dependent phase of drug use, underwent multiple hospital admissions but stayed for a shorter period and faced more deaths, when compared to those who did not shift.
Conclusion: In clinic-attending male patients with buprenorphine dependence who were followed-up although dependent pattern of use of the drug continued for a long time in their career, there was a slow but progressive improvement. Transition to other drugs was associated with a worse course and outcome as compared to being stable on buprenorphine.