Prolonged recovery after diazepam sedation: The influence of food, charcoal ingestion and injection rate on the effects of intravenous diazepam

Abstract

Summary: Thirteen subjects received diazepam 0.3 mg/kg i.v. twice with a 2-week interval between the doses. In seven subjects who had eaten at 3 h after the injection, reactive skills in a choice reaction test were impaired significantly (P< 0.05) and there was a 20% increase in the serum diazepam concentrations at 5 h. When the meal was eaten at 7 h, a 50% increase (P<0.01) in the serum diazepam concentration was not associated with a significant impairment in psychomotor skills. In a second group of six subjects charcoal ingestion failed to hasten the clearance of diazepam from serum, and did not affect recovery of co-ordinative skills. In a third group of 12 subjects receiving diazepam 0.15 mg/kg i.v. twice at an interval of 2 weeks, the rapid injection of diazepam resulted in a significantly greater (P < 0.05) degree of drooping of the upper eyelid and in a greater incidence of amnesia to abdominal pinching. The subjects also experienced more pain in the arm during the faster injection (P<0.01). Late effects on psychomotor skills were similar with both rates of injection. The results suggest that the immobilization of diazepam from its storage site after food intake induces a late impairment of psychomotor skills, especially if the food is eaten within less rhnn 5 h after the injection. A rapid i.v. injection of diazepam induces greater sedative and amnesic effects than a slow injection of the same dose, but the slow injection of a greater dose is preferable because of the possibility of thrombophlebitis after rapid injection. © 1976 Macmillan Journals Ltd.