Effects of naloxone on the subjective and psychomotor effects of nitrous oxide in humans.

Two double-blind, randomized experiments tested whether the opioid antagonist naloxone alters the mood-altering and performance-impairing effects of nitrous oxide. In both experiments, inhaling 30% nitrous oxide increased self-reported feelings of drug effect, carefreeness, drunkenness, sedation, and being high, and it worsened psychomotor performance. Naloxone, given intravenously at doses ranging from 0.01 to 10 mg per 70 kg, had no effects on its own and did not significantly change any of nitrous oxide's effects. The authors conclude that naloxone, at doses up to 10 mg, does not appear to influence the subjective or psychomotor effects of nitrous oxide.

Study at a glance

Abstract

The effects of naloxone on the mood-altering and psychomotor-impairing effects of nitrous oxide were examined in two studies. Each of the double-blind, randomized trials tested effects of three doses of naloxone or saline placebo during inhalation of 30% nitrous oxide in oxygen or 100% oxygen placebo. Experiment 1 tested a range of naloxone doses used clinically to reverse opiate-induced respiratory depression (0, 0.01, 0.1 1.0 mg/70 kg) and Experiment 2 included a dose approximately 25 times higher than that needed to reverse opiate-induced respiratory depression (0, 1.0, 3.0, 10 mg/70 kg). Nitrous oxide increased subject-rated reports of "feel drug effect," "carefree," "drunk," "sedated," and "high", and decreased psychomotor performance in both experiments. Naloxone had no effects by itself in either experiment, and, for the most part, did not significantly interact with nitrous oxide-induced changes in mood or psychomotor performance. Naloxone, in doses of 10 mg or less, does not appear to affect the subjective and psychomotor effects of nitrous oxide.