Effects of etomidate given in repeated doses

Fifty fit, female patients were given four consecutive intravenous doses of etomidate 10 mg, so as to maintain sleep, after establishment of epidural block for postpartum sterilization. A matched group was given four doses of thiopentone 125 mg. Cumulative hypnotic effect, as judged by increasing sleep duration with second and subsequent doses, was much less with etomidate than with thiopentone. Etomidate did not depress blood pressure, whereas it fell progressively with successive doses of thiopentone. Injection pain was reported in 68% of patients receiving etomidate, and this tended to increase with successive doses; 12% also showed local inflammation at the injection site. Tremor, due to etomidate, was common, but did not increase with successive doses. Feelings of sleepiness, lasting several hours after waking, were more common after thiopentone than after etomidate.