Ranitidine treatment and cortisol metabolism in man

Experimental evidence suggested that H2-receptor antagonists may inhibit not only hepatic but also adrenal cytochrome P-450 dependent monooxygenases. Therefore, the effects of ranitidine (150 mg b.i.d. over 14 days) on cortisol metabolism and antipyrine clearance have been investigated in nine healthy volunteers. Urinary excretion of 6 beta-hydroxycortisol (6 beta-OHC) and 17-hydroxycorticosteroids (17-OHCS) remained unaffected by ranitidine pretreatment, as did the calculated 6 beta-OHC/17-OHCS ratio. Only marginal effects were observed on antipyrine kinetics and metabolite formation. We conclude that neither adrenal production of corticosteroids nor their hepatic metabolism is affected by ranitidine administration.