title: Oxazepam does not modulate the behavioral effects of d-amphetamine in humans.
abstract: Benzodiazepines, which are gamma-aminobutyric acid-A (GABA(A)) receptor positive modulators, can block the behavioral effects of psychomotor stimulants. In the present study, the ability of oxazepam, which may have less abuse potential compared to some other benzodiazepines, to attenuate the discriminative-stimulus, subject-rated and psychomotor performance effects of d-amphetamine in humans was determined. Six healthy participants (2 female, 4 male) learned to discriminate 15 mg oral d-amphetamine. After acquiring the discrimination (i.e., > or = 80% correct responding on 4 consecutive days), the effects of d-amphetamine (0, 2.5, 5, 10 and 15 mg), alone and in combination with acutely administered oxazepam (0 and 20 mg) were assessed. d-Amphetamine alone functioned as a discriminative stimulus, produced stimulant-like subject-rated effects (e.g., increased ratings of Stimulated on a Drug-Effect Questionnaire) and enhanced psychomotor performance. Oxazepam alone increased subject ratings of sedation (e.g., increased ratings of Sluggish, Fatigued and Lazy on a Drug-Effect Questionnaire) and impaired psychomotor performance. Oxazepam alone did not occasion d-amphetamine-like discriminative-stimulus effects, and had no effect on the discriminative-stimulus or subject-rated effects of d-amphetamine when given in combination. The results of this experiment are discordant with previous research and suggest that benzodiazepines differ in their ability to modulate the behavioral effects of d-amphetamine.
authors.affiliation: Department of Behavioral Science, College of Medicine, University of Kentucky, Lexington, KY 40536-0086, United States.
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Lile
authors.forename: William W
authors.initials: WW
authors.lastname: Stoops
authors.forename: Frances P
authors.initials: FP
authors.lastname: Wagner
authors.forename: Paul E A
authors.initials: PE
authors.lastname: Glaser
authors.forename: Craig R
authors.initials: CR
authors.lastname: Rush
mesh_terms: D000328:Adult; D019969:Amphetamine-Related Disorders / Q000523:psychology; D001519:Behavior / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D003913:Dextroamphetamine / Q000494:pharmacology*; D004192:Discrimination, Psychological / Q000187:drug effects*; D004311:Double-Blind Method; D004347:Drug Interactions; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D008297:Male; D010076:Oxazepam / Q000494:pharmacology*; D011597:Psychomotor Performance / Q000187:drug effects; D011795:Surveys and Questionnaires
chemical_list: D000697:Central Nervous System Stimulants; D006993:Hypnotics and Sedatives; D010076:Oxazepam; D003913:Dextroamphetamine