Inhibition of Steroidogenesis by Cimetidine in Man: A Double-Blind, Prospective Study

Abstract

This article concerns a double-blind, prospective, study. The experiments were performed in 10 adult male volunteers, scheduled for major abdominal vascular surgery. The effect of cimetidine on the steroidogenesis was compared with the effect of ranitidine. There proved to be a 40% reduction in the serum Cortisol concentration in the group of patients treated with cimetidine. In the ranitidine group it was not possible to demonstrate a significant decrease of the serum Cortisol concentration. Cimetidine is a drug containing a free imidazole ring. Imidazoles can bind to the cytochrome P-450. The lack of clinical phenomena caused by a blockade of the cytochrome P-450 is not exactly understood. For that reason, this study was extended. At the end of the first study, ascorbic acid was administered, as in case of etomidate. The reversibility of the blockade could be demonstrated also in the case of cimetidine. The serum Cortisol concentrations increased only in the case of cimetidine. This was not seen in the group receiving ranitidine.

Key Words:

• Ascorbic acid
• metabolism
• blockade of steroidogenesis
• cimetidine
• Cortisol
• metabolism
• ranitidine