Effects of alprazolam, caffeine, and zolpidem in humans trained to discriminate triazolam from placebo.
This study compared the discriminative stimulus effects of zolpidem, a nonbenzodiazepine hypnotic, to benzodiazepines. Eight participants learned to discriminate triazolam (0.35 mg/70 kg) from placebo. The discriminative stimulus effects, self-reported subjective effects, and performance effects of triazolam (0.05-0.35 mg/70 kg), alprazolam (0.25-1.75 mg/70 kg), zolpidem (2.5-35 mg/70 kg) and caffeine (75-525 mg/70 kg) were assessed under two-response and novel-response drug discrimination procedures. Under the two-response procedure, triazolam, alprazolam and zolpidem fully substituted for triazolam and caffeine did not. Under the novel-response procedure, triazolam and alprazolam substituted for triazolam and zolpidem partially substituted for triazolam. Zolpidem, but not triazolam or alprazolam, also produced some novel responding. Caffeine produced both placebo-appropriate and novel responding. The self-reported effects of triazolam, alprazolam and zolpidem were similar. Overall, zolpidem produced similar, but not identical, effects as the benzodiazepines.
Smith
B J
BJ
Departments of Psychiatry and Psychology, University of Vermont, Burlington, VT 05401, USA. brandi@jhmi.edu
Bickel
W K
WK
D000293:Adolescent; D000328:Adult; D000525:Alprazolam / Q000494:pharmacology*; D000704:Analysis of Variance; D002110:Caffeine / Q000494:pharmacology; D004192:Discrimination, Psychological / Q000187:drug effects* / Q000502:physiology; D005260:Female; D018755:GABA Agonists / Q000494:pharmacology*; D018757:GABA Modulators / Q000494:pharmacology*; D006801:Humans; D008297:Male; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology*; D014229:Triazolam / Q000494:pharmacology*; D000077334:Zolpidem
D018755:GABA Agonists; D018757:GABA Modulators; D010726:Phosphodiesterase Inhibitors; D011725:Pyridines; D014229:Triazolam; D002110:Caffeine; D000077334:Zolpidem; D000525:Alprazolam