Experimental assessment of the relative abuse liability of triazolam and pentobarbital

There has been increasing interest in assessing the abuse liability of benzodiazepines relative to the barbiturates and determining whether there are differences between individual benzodiazepines in terms of abuse liability. One of the best validated human experimental methodologies for providing information relevant to abuse liability is to evaluate the subjective and/or reinforcing effects of psychoactive substances in subjects with histories of drug abuse. The present report describes findings from a recent study which compared the effects of triazolam (TZ) (a benzodiazepine hypnotic) and pentobarbital (PTB) in subjects with histories of sedative drug abuse. The experimental approach involved both the assessment of the liability for abuse (likelihood) through the use of subjects rating scales and the assessment of the liability of abuse (associated hazard) through the use of objective performance measures and subject ratings of task performance. The results clearly indicate that with acute dosing, TZ has a lower liability (likelihood) for abuse than PTB.