The influence of the route of administration on the clinical action of diazepam

Abstract

The relative efficacy of diazepam 10 mg as a premedicant was assessed following its oral and intramuscular administration, using a "double-blind, double-dummy" technique, as well as its effect when given by both routes. Drugs were given to a standard patient population who were undergoing the same type of operation and receiving a standard anaesthetic. The most rapid onset of soporific action occurred when diazepam was given by mouth and this produced the best effect throughout the period of the study although its efficacy began to pass off after 60 minutes. It was superior in effect to the same dose injected into the thigh. The combined effect of oral and intramuscular diazepam was not notably greater than tht of the single oral dose. The injection of diazepam was followed by an unacceptably high incidence of pain, particularly when this was given into the thigh. There were no significant differences in either the course of anaesthesia or the incidence of post-operative nausea and vomiting. When the undesired effects are taken into consideration, the oral administration of diazepam should be the route of choice.