Subjective Responses to Six Common Preoperative Medications

Abstract

Three controlled, double-blind studies of 6 commonly used preoperative medications were carried out to evaluate their effects on patients'' sleepiness, apprehension, restlessness and confusion and to determine the incidences of side-effects. Separate studies each dealt with 2 barbiturates, an antihistaminic and a minor tranquilizer and 2 narcotic analgesics: 1st a treatment was pentobarbital, 50 or 150 mg, sodium secobarbital, 50 or 150 mg or placebo; 2nd a treatment was diazepam, 5, 10 or 15 mg, hydroxyzine, 50, 100 or 150 mg or placebo and 3rd morphine, 5 or 10 mg, meperidine, 50 or 100 mg or placebo. Each patient received only 1 treatment; it was randomly assigned and administered i.v. 90 min before operation. Approximately 30 patients received each treatment. There were 509 subjects in the entire investigation. Subjective responses, scored on a scale of 0-9, were obtained 30 and 60 min after the injection was administered and were compared with baseline responses obtained before treatment. Independent ratings were also made by a nurse-observer and an overall evaluation was provided by an anesthesiologist. Interview and medication times were controlled to assure standard measurements throughout all 3 studies. Five (except diazepam) increased patients'' subjective ratings of sleepiness and the effects were dose-related. None had any significant effect upon postmedication apprehension as reported by the patients. The only frequently observed side effects, found with all 6 premedicants, were dry mouth and slurred speech.