Cortisol and dexamethasone elimination during treatment with cimetidine.

In a randomised cross-over study of treatment for 7 days with cimetidine 600 mg twice daily and placebo, cimetidine had no effect on the pharmacokinetics of a single intravenous dose of dexamethasone sodium phosphate. Likewise the elimination characteristics of endogenous cortisol in the dexamethasone suppressed state were not affected by cimetidine.