buprenorphine and propiram

The purpose of the present study was to examine the effects of the partial agonists of the morphine type, buprenorphine, profadol and propiram on the spinally-mediated C-fiber reflex. Buprenorphine, profadol and propiram facilitated the C-fiber reflex. In the presence of naltrexone, the effects of buprenorphine were changed to depression of the C-fiber reflex. Profadol and propiram continued to facilitate the C-fiber reflex in the presence of naltrexone. The present results suggest that buprenorphine facilitated the C-fiber reflex by blocking endogenous opioid peptide inhibition of the C-fiber reflex whereas profadol and propiram facilitated it by a non-opioid mechanism.

Topics: Analgesics; Animals; Buprenorphine; Cats; Decerebrate State; Female; Male; Nerve Fibers; Pyridines; Pyrrolidines; Reflex

Nine mixed agonist-antagonist opioids were evaluated in macaque monkeys for their ability to serve as positive reinforcers and for their discriminative stimulus similarity to etorphine and ethylketazocine. For tests of reinforcing properties, various doses of each drug were substituted for codeine under a fixed-ratio 30 time-out 600 sec schedule of i.v. delivery. Discriminative properties were assessed in separate groups of monkeys for which etorphine and saline, or ethylketazocine and saline, were established as discriminative stimuli for responses maintained under a fixed-ratio 20 schedule of food delivery. Two patterns of reinforcing and discriminative stimulus properties were observed. Buprenorphine, butorphanol, GPA 1657, nalbuphine, propiram and WY 16225 (dezocine) functioned as positive reinforcers and occasioned etorphine-appropriate but not ethylketazocine-appropriate responses. dl-Profadol also functioned as a positive reinforcer; its stereoisomers occasioned etorphine-appropriate but not, in general, ethylketazocine-appropriate responses. In contrast, levallorphan and oxilorphan did not function as positive reinforcers and occasioned ethylketazocine-appropriate but no more than 30% etorphine-appropriate responses. Under these experimental conditions, the reinforcing and discriminative stimulus profiles of the mixed agonist-antagonist opioids paralleled those of etorphine-like (mu) or ethylketazocine-like (kappa) opioid agonists.

Topics: Animals; Bridged Bicyclo Compounds, Heterocyclic; Buprenorphine; Butorphanol; Cycloparaffins; Discrimination Learning; Female; Levallorphan; Macaca mulatta; Male; Morphinans; Nalbuphine; Narcotic Antagonists; Narcotics; Pyridines; Pyrrolidines; Reinforcement, Psychology; Tetrahydronaphthalenes