Reinforcing, subjective, and psychomotor effects of sevoflurane and nitrous oxide in moderate-drinking healthy volunteers.
OBJECTIVE
To characterize the reinforcing, subjective and psychomotor effects of sevoflurane, a volatile anesthetic, across a range of subanesthetic concentrations in non-drug-abusing humans. In addition, a concentration of nitrous oxide was included in the design in order to compare and contrast behavioral effects of a gaseous to a volatile anesthesic.


METHODS
Repeated measures, double-blind, placebo control experiment.


METHODS
Human psychopharmacology laboratory.


METHODS
Fourteen moderate-drinking healthy volunteers.


METHODS
In each of four sessions, subjects first sampled placebo-oxygen and an active drug (end-tidal concentrations of 0.2, 0.4, 0.6% sevoflurane and 30% nitrous oxide in oxygen) and then chose between the two


METHODS
Mood and psychomotor performance during the sampling trials, and choice of drug or placebo-oxygen during choice trial.


RESULTS
Nitrous oxide was chosen by 71% of the subjects, and 0.2, 0.4 and 0.6% sevoflurane were chosen by 50%, 57% and 50% of the subjects, respectively. Neither drug was chosen at levels that exceeded that of chance. Sevoflurane and nitrous oxide both impaired psychomotor performance and produced changes in mood. There were several differences in subjective effects between sevoflurane and nitrous oxide at concentrations which were considered to be equivalent in anesthetic effect. Finally, although sevoflurane did not function as a reinforcer in the majority of individuals tested, there was evidence that sevoflurane functioned as a reinforcer in some volunteers: subjects who chose to inhale sevoflurane over placebo-oxygen tended to report a positive spectrum of subjective effects during the sevoflurane sampling trial, relative to those subjects who chose placebo-oxygen over sevoflurane.


CONCLUSIONS
Although sevoflurane did not function as a reinforcer in the majority of subjects tested, the correspondence between positive subjective effects of sevoflurane and subsequent sevoflurane choice suggests that the volatile anesthetic drug can function as a reinforcer in some moderate drinkers.
Zacny
J P
JP
Department of Anesthesia and Critical Care, University of Chicago, USA. zacn@midway.uchicago.edu
Janiszewski
D
D
Sadeghi
P
P
Black
M L
ML
D000328:Adult; D000339:Affect / Q000187:drug effects; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D002755:Choice Behavior; D003258:Consumer Behavior; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008738:Methyl Ethers / Q000494:pharmacology*; D009609:Nitrous Oxide / Q000494:pharmacology*; D011597:Psychomotor Performance / Q000187:drug effects*; D012054:Reinforcement, Psychology; D012677:Sensation / Q000187:drug effects; D000077149:Sevoflurane
D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane; D009609:Nitrous Oxide