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.
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.
Drug and alcohol dependence
December 1, 1994
S Yajnik, P Thapar, J L Lichtor et al.
An experiment compared marijuana users and non-users to see if their history with cannabis affected how they responded to nitrous oxide. Participants first sampled both 40% nitrous oxide in oxygen and a placebo (100% oxygen), then chose which to inhale in later sessions. Both groups chose nitrous oxide less than half the time, and the choice patterns did not differ significantly between marijuana users and non-users. However, marijuana users reported stronger subjective effects from nitrous oxide, suggesting a history of marijuana use may intensify some of the drug's subjective experiences.
Pharmacology, biochemistry, and behavior
November 1, 1994
J P Zacny, D W Coalson, J L Lichtor et al.
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.
Psychopharmacology
April 1, 1994
J P Zacny, G Sparacino, P Hoffmann et al.
In nine healthy volunteers, isoflurane and nitrous oxide produced similar subjective effects like feeling drunk and spaced out, but isoflurane uniquely increased confusion, sedation, and carefreeness while reducing perceived control over thoughts and body; it also had an unpleasant odor. Psychomotor performance was more impaired by isoflurane than by nitrous oxide, but recovery from both was rapid and complete within five minutes. Both drugs impaired immediate and delayed free recall. The findings suggest isoflurane may be less suitable than nitrous oxide for conscious sedation due to its greater psychomotor effects and unpleasant odor.
Drug and alcohol dependence
February 1, 1993
C S Dohrn, J L Lichtor, D W Coalson et al.
In healthy volunteers, inhaling 30% nitrous oxide was chosen no more often than oxygen (41.6% choice rate), showing it was not more reinforcing. Inhaling 40% nitrous oxide was chosen significantly less often than oxygen (22% choice rate), indicating it was less reinforcing. Nitrous oxide produced robust subjective effects such as increased ratings of 'high,' 'tingling,' and 'dizzy.' Subjects who chose nitrous oxide reported pleasant effects and liked it, while those who chose placebo reported unpleasant effects and disliked it. Both concentrations impaired psychomotor performance in all subjects. The lack of reinforcing effects is discussed in light of nitrous oxide's known abuse potential.