Pharmacology, biochemistry, and behavior
June 1, 1996
S Yajnik, J P Zacny, C J Young et al.
A crossover, double-blind trial with eleven healthy volunteers tested whether acute drug tolerance develops to the subjective, cognitive, and psychomotor effects of subanesthetic nitrous oxide at doses of 0, 10, 20, 30, and 40%. Over a 120-minute inhalation period, there was little evidence of acute tolerance to the subjective or impairing effects at any concentration.
Neuroscience letters
May 10, 1996
J P Zacny, A M Cho, D W Coalson et al.
Inhaling nitrous oxide at increasing doses (10–40%) reduces pain intensity and the bother of pain from cold-water immersion, but this analgesic effect weakens over a 120-minute inhalation period (acute tolerance). Some pleasant subjective effects, such as elation and drug liking, also show acute tolerance. Other subjective effects and psychomotor impairment do not change significantly during the inhalation period, indicating no acute tolerance for those measures. The differing patterns of tolerance suggest that distinct neurochemical systems may mediate different effects of nitrous oxide.
Pharmacology, biochemistry, and behavior
August 1, 1995
J P Zacny, S Yajnik, D Coalson et al.
In two double-blind, randomized, crossover trials, eight healthy volunteers inhaled 30% nitrous oxide in oxygen for 35 minutes and were given flumazenil 10 minutes into the inhalation. Experiment 1 tested clinical doses of flumazenil (0, 0.25, 0.5, and 1.0 mg/70 kg), while Experiment 2 tested a supraclinical dose (0 and 5.0 mg/70 kg). Nitrous oxide increased ratings of high, drunk, and tingling and impaired psychomotor performance. Only the supraclinical flumazenil dose significantly reduced the high rating; other subjective effects showed non-significant decreases. Flumazenil did not affect nitrous oxide's psychomotor effects. The findings suggest that a high flumazenil dose may partially antagonize some subjective effects of nitrous oxide.