Preclinical evaluation of the abuse potential of the analgesic bicifadine

J Pharmacol Exp Ther. 2009 Jul;330(1):236-48. doi: 10.1124/jpet.109.150540. Epub 2009 Apr 8.

Abstract

The abuse liability of the analgesic bicifadine was investigated in animal models used to predict the abuse potential of psychostimulants in humans. Bicifadine, cocaine, d-amphetamine, bupropion, and desipramine were evaluated for the production of cocaine-like discriminative stimulus effects in rats. Cocaine, d-amphetamine, and bupropion dose-dependently and fully substituted for cocaine. Bicifadine and desipramine produced a maximum mean cocaine-lever selection of 80 and 69%, respectively, but doses yielding peak substitution strongly suppressed response rates. Microdialysis studies in normal waking rats indicated that d-amphetamine increased dopamine levels in the nucleus accumbens and striatum to a much greater degree than bicifadine, but bicifadine increased 5-hydroxytryptamine levels in the nucleus accumbens and striatum more than d-amphetamine. Bicifadine was also tested for intravenous self-administration in rhesus monkeys experienced with cocaine administration. Reinforcing effects of bicifadine were observed in only two of four subjects, whereas cocaine, d-amphetamine, and bupropion served as reinforcers in all four monkeys. When evaluated under a progressive ratio procedure, no dose of bicifadine maintained responding to the extent of cocaine, d-amphetamine, or bupropion. The discriminative stimulus effects associated with bicifadine were similar, but not identical, to those of psychostimulants. Although bicifadine maintained self-administration behavior in some subjects, its reinforcing efficacy was very low relative to cocaine, d-amphetamine, and bupropion. These results are consistent with the microdialysis findings of lower dopamine levels and higher 5-hydroxytryptamine levels after administration of bicifadine relative to d-amphetamine. Overall, the current findings support a low abuse potential of bicifadine, more resembling that of antidepressants than psychostimulants.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analgesics / administration & dosage*
  • Animals
  • Brain / drug effects
  • Brain / metabolism
  • Bridged Bicyclo Compounds, Heterocyclic / administration & dosage*
  • Discrimination Learning / drug effects
  • Discrimination Learning / physiology
  • Dose-Response Relationship, Drug
  • Drug Evaluation, Preclinical / methods
  • Macaca mulatta
  • Male
  • Rats
  • Rats, Sprague-Dawley
  • Self Administration
  • Substance-Related Disorders / etiology
  • Substance-Related Disorders / metabolism*

Substances

  • Analgesics
  • Bridged Bicyclo Compounds, Heterocyclic
  • bicifadine