Secobarbital in humans discriminating triazolam under two-response and novel-response procedures.
Humans were trained to discriminate the benzodiazepine triazolam (0.32 mg/70 kg) from placebo under a two-response (drug vs. placebo) drug discrimination procedure. Dose-effect curves for several drugs were then determined in a crossover design using the two-response procedure and a 'novel-response procedure' that provided a novel-appropriate response for drugs unlike triazolam or placebo. Three subjects were tested with triazolam (0.1-0.32 mg/70 kg), the barbiturate secobarbital (56-177 mg/70 kg), and caffeine (320 and 560 mg/70 kg). Triazolam dose dependently increased triazolam-appropriate responding under both procedures and generally did not occasion novel-appropriate responding under the novel-response procedure. Secobarbital substituted for triazolam in the two-response procedure and dose-dependently increased novel-appropriate responding as well as occasioned some triazolam-appropriate responding in the novel-response procedure. Caffeine generally occasioned placebo-appropriate responding under the two-response procedure and a mix of novel- and placebo-appropriate responding under the novel-response procedure. Triazolam and secobarbital produced qualitatively similar self-reported drug effects. These results suggest that the novel-response procedure for human drug discrimination may enhance the pharmacological selectivity of triazolam- and placebo-appropriate responding.
Kamien
J B
JB
Human Behavioral Pharmacology Laboratory, University of Vermont, Burlington 05401, USA.
Bickel
W K
WK
Smith
B J
BJ
Badger
G J
GJ
Hughes
J R
JR
D000328:Adult; D002110:Caffeine / Q000494:pharmacology; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D018592:Cross-Over Studies; D004193:Discrimination Learning / Q000187:drug effects; D004192:Discrimination, Psychological / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D012631:Secobarbital / Q000494:pharmacology*; D014229:Triazolam / Q000494:pharmacology*
D000697:Central Nervous System Stimulants; D006993:Hypnotics and Sedatives; D014229:Triazolam; D012631:Secobarbital; D002110:Caffeine