Self-injection of barbiturates, benzodiazepines and other sedative-anxiolytics in baboons

Psychopharmacology (Berl). 1991;103(2):154-61. doi: 10.1007/BF02244196.

Abstract

Self-injection of 12 sedative-anxiolytics was examined in baboons. Intravenous injections and initiation of a 3-h time-out were dependent upon completion of a fixed-ratio schedule requirement, permitting eight injections per day. Before testing each dose of drug, self-injection performance was established with cocaine. Subsequently, a test dose was substituted for cocaine. At some doses, all five of the benzodiazepines examined (alprazolam, bromazepam, chlordiazepoxide, lorazepam, triazolam) maintained rates (number of injections per day) of drug self-injection above vehicle control in each of the baboons tested. Maximum rates of benzodiazepine self-injection were generally submaximal. Of the benzodiazepines examined, triazolam maintained the highest rates of self-injection. Among the three barbiturates tested, methohexital generally maintained high rates of self-injection in contrast to hexobarbital and phenobarbital, which only maintained low rates. Of the four non-benzodiazepine non-barbiturate sedatives examined, both chloral hydrate and methyprylon occasionally maintained high rates of self-injection. Although there were differences within and across animals, baclofen maintained intermediate rates of self-injection. The novel anxiolytic buspirone maintained only low rates of self-injection that were not different from vehicle. This study further validates the self-injection methodology for assessing sedative-anxiolytic abuse liability and provides new information about drug elimination rate as a determinant of drug self-administration.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Anti-Anxiety Agents / pharmacology*
  • Barbiturates / pharmacology*
  • Behavior, Animal / drug effects
  • Benzodiazepines
  • Cocaine / pharmacology
  • Feeding Behavior / drug effects
  • Housing, Animal
  • Hypnotics and Sedatives / pharmacology*
  • Injections, Intravenous
  • Male
  • Papio
  • Reinforcement Schedule
  • Self Administration*

Substances

  • Anti-Anxiety Agents
  • Barbiturates
  • Hypnotics and Sedatives
  • Benzodiazepines
  • Cocaine