Abstract
Self-injection of three barbiturates, six benzodiazepines, and chlorpromazine was examined in baboons. Intravenous injections of drug were dependent upon completion of 160 lever presses (a 160-response fixed-ratio schedule). A 3-h time-out period followed each injection, permitting a maximum of eight injections per day. Prior to testing each dose of drug, self-injection performance was established with cocaine. Subsequently, a test dose was substituted for cocaine. Amobarbital, pentobarbital, and secobarbital maintained the highest levels of self-injection, which were similar to those maintained by cocaine. Clonazepam, clorazepate, diazepam, flurazepam, medazepam, and midazolam maintained relatively modest levels of self-injection, while chlorpromazine maintained only low levels, which were in the range of vehicle control. Of the six benzodiazepines, midazolam produced the highest levels of self-injection. At the highest self-injected doses, the barbiturates produced anesthesia in contrast to the benzodiazepines, which produced only sedation. None of the drugs affected food intake except for chlorpromazine, which produced dose-related decreases. The differences among the drug classes (i.e., barbiturate, benzodiazepine, phenothiazine) with respect to the maintenance of self-injection correspond well with the results of previous animal and human drug self-administration studies.
Original language | English (US) |
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Pages (from-to) | 101-109 |
Number of pages | 9 |
Journal | Psychopharmacology |
Volume | 75 |
Issue number | 2 |
DOIs | |
State | Published - Nov 1981 |
Keywords
- Amobarbital
- Baboons
- Chlorpromazine
- Clonazepam
- Clorazepate
- Cocaine
- Diazepam
- Drug self-administration
- Flurazepam
- Medazepam
- Midazolam
- Pentobarbital
- Secobarbital
ASJC Scopus subject areas
- Pharmacology