Effect of buprenorphine on psychomotor functions in patients on buprenorphine maintenance

Abstract

Patients on buprenorphine maintenance for opioid dependence often abuse its additional doses over and above the maintenance dose. Being a psychoactive agent, it may affect psychomotor performance with all its consequences, for example, effect on quality of life. This study was conducted to assess the effects of its additional doses on psychomotor performance in patients who are maintained on it. This was an interventional study, carried out in an in-patient setting in a tertiary care national drug dependence treatment center. It included 19 subjects maintained on buprenorphine, 4 mg/d (s/L) for at least a month. Maintenance dose was followed by three administrations of buprenorphine, 2 mg, at two hourly intervals (cumulative dose design). Subjects were assessed on digit symbol substitution test, trail making, digit span, and delayed recall, after each administration and the next morning. Performance of subjects on Digit Symbol Substitution Test (chi2 = 52.98, p < 0.000) and Trail Making Test-A (chi2 = 26.29, p < 0.000) and B (chi2 = 42.08, p < 0.000) improved significantly with each assessment while other tests were unaffected. Improvement in psychomotor performance (which could be true effect of drug itself or a result of other factors, eg, inadequate maintenance dose or practice effect) though contrasting with some of the earlier findings, does have significant clinical implications regarding the long-term use of buprenorphine. It would be worthwhile repeating this type of study in a placebo controlled design to further verify the results.