Fig. 5.

The effects of chronic buprenorphine on the antinociceptive and behaviorally disruptive effects of opioid partial agonists. The ability of buprenorphine, butorphanol, and nalbuphine to produce increases in tail withdrawal latency (top panels) or decreases in food-maintained behavior (bottom panels) before and during chronic buprenorphine treatment (0.1 and 0.32 mg/kg per day). Abscissae: dose (milligrams per kilogram) of opioid partial agonist administered using cumulative dosing. Ordinates: latency to withdraw tail from 55°C water (seconds) (top panels) and response rate (responses/second) (bottom panels).