Profiling the subjective, psychomotor, and physiological effects of a hydrocodone/acetaminophen product in recreational drug users.

BACKGROUND: Hydrocodone (HYD) is a mu opioid agonist. Hydrocodone/acetaminophen HYD/ACET compounds are both widely prescribed and abused prescription painkillers in the United States. In the present study, we profiled the subjective, psychomotor, and physiological effects of the compound. It was of particular interest to determine if HYD/ACET had abuse liability-related subjective effects in a population of recreational drug users.

METHODS: Eighteen volunteers participated in a crossover, randomized, double-blind study in which they received, all p.o., placebo; 5 mg HYD/500 mg ACET; 10mg HYD/500 mg ACET; 20 mg HYD/1000 mg ACET; 40 mg morphine (MOR) sulfate; and 1000 mg ACET. Measures were assessed before and for 300 min after drug administration.

RESULTS: HYD/ACET produced effects that were dose-related, and the highest dose produced a similar magnitude of effect to that of MOR. There were some abuse liability-related subjective effects produced by 20 mg HYD/ACET and MOR, but there were also unpleasant effects. Some unpleasant subjective effects were experienced only by females. Overall liking and "take again" ratings assessed 24 h post-session were not significant, but several subjects had elevated liking and "take again" ratings at this time in one or more of the HYD/ACET conditions and/or in the MOR condition. Both 20 mg HYD/1000 mg ACET and MOR impaired psychomotor performance. HYD/ACET and MOR produced miosis.

CONCLUSIONS: HYD/ACET produced some abuse liability-related subjective effects in recreational drug users, which is consistent with the widespread non-medical use and abuse of this product.