LAUSR

BACKGROUND Buprenorphine is widely used in the treatment of opioid use disorder and pain management. Little is known about the analgesic effects of high-dose sublingual buprenorphine, particularly in doses of >8 mg. The aim of this study was to examine the effect of ascending doses of buprenorphine upon acute pain measures in patients stabilized on buprenorphine as treatment for opioid dependence. METHODS The pilot study (n = 7) was a randomised, controlled, double-blind, double-dummy, within-subject crossover study examining cold-pressor threshold and tolerance testing under different buprenorphine dose conditions. Each participant attended three sessions to test the analgesic effect of buprenorphine in their usual dose (100%), 150% and 200% of their usual daily dose. RESULTS No significant effects of increased dose were seen on experimental pain measures. Expected physiological effects on pupil size and pulse were observed with increasing dose. No effect of buprenorphine condition was seen on subjective ratings of drug strength, or self-reported sedation, though lower ratings drug liking were seen with 150% and 200% conditions, and lower ratings of 'bad effects' and intoxication were reported with the 200% buprenorphine dose condition. No safety concerns with the 150 and 200% buprenorphine dose condition were observed. DISCUSSION This pilot study suggests that a ceiling effect on analgesia may be observed in people maintained on buprenorphine, though larger studies may confirm this finding. Clinical Trial Number: ACTRN12614001038684.