Behavioral pharmacological similarities between methylphenidate and cocaine in cocaine abusers.

Six human participants with recent histories of cocaine use were trained to discriminate 200 mg oral cocaine hydrochloride. A range of doses of oral cocaine (50–300 mg), methylphenidate (15–90 mg), triazolam (0.125–0.75 mg), and placebo were then tested to determine whether they shared discriminative–stimulus and participant-rated effects with 200 mg cocaine. Cocaine and methylphenidate dose-dependently increased cocaine-appropriate responding, produced prototypical stimulant-like participant-rated drug effects (e.g., increased participant ratings of Drug Liking), and increased heart rate and blood pressure. Triazolam produced low levels of cocaine-appropriate responding and impaired performance. Thus, consistent with previous studies, humans can reliably discriminate oral cocaine. Consistent with in vivo behavioral neuropharmacological data, the discriminative–stimulus, participant-rated, and physiological effects of oral cocaine and methylphenidate were similar. (PsycINFO Database Record (c) 2010 APA, all rights reserved)