Cognitive functioning in patients maintained on buprenorphine at peak and trough buprenorphine levels: An experimental study.

ABSTRACT

OBJECTIVES: To assess the cognitive functions in participants maintained on buprenorphine for opioid dependence at peak and trough buprenorphine levels. METHODS: This was a double-blind, randomized, experimental study. Sixty participants maintained on buprenorphine were matched for age and education and randomly allocated to "peak" group or "trough" group. The "peak" group received buprenorphine two hours before assessment, whereas the trough group received placebo. The cognitive domains of attention, learning and memory, and executive function including fluency, working memory, response inhibition and set shifting were tested. RESULTS: The two groups were comparable on socio-demographic, substance use profile and opioid agonist treatment-related characteristics. Significant differences in performance of peak and trough group were observed on Wisconsin Card Sorting Test parameters of number of correct responses (U = 289.00, p = 0.03), number of errors (t = 02.26, df = 58, p = 0.03), and perseverative errors (U = 301.50, p = 0.04). CONCLUSIONS: The time since buprenorphine dose has significant relation on specific cognitive tasks in patients maintained on buprenorphine for opioid dependence.