THE ROLE OF ASCORBIC-ACID AND XYLITOL IN ETOMIDATE-INDUCED ADRENOCORTICAL SUPPRESSION IN HUMANS

Etomidate-induced suppression of cortisol biosynthesis is a result of a blockade of 11-beta-hydroxylation in the adrenal gland, mediated by the imidazol radical of etomidate. Since the generation of steroids re quires reductive and energy rich equivalents, the present study examin ed whether supplementation with ascorbic acid or xylitol, a major sour ce of NADPH, could attenuate adrenal suppression by etomidate in human subjects by promoting the turnover rate of 11-beta-hydroxylase. Durin g continuous etomidate/alfentanil anaesthesia for pelviscopic surgery 30 female patients received either Ringer's lactate, xylitol (0.25 g k g(-1) h(-1)) or ascorbic acid (0.5 g h(-1)) intravenously (i.v.). The plasma concentrations of cortisol, aldosterone and dehydroepiandroster one (DHEA) were recorded for 5 h after end of surgery and a stimulatio n with synthetic ACTH was performed. The results showed no evidence of a clinically relevant attenuating effect of ascorbic acid or xylitol on etomidate-induced adrenocortical suppression. However, the observed suppression of cortisol levels was not enough to allow an attenuating affect to be measured.