title: Effect of cimetidine on the absorption of orally administered tetracycline.
abstract: 1 Six healthy female subjects received orally two 250 mg tetracycline tablets either with 400 mg cimetidine or placebo. In a separate experiment six healthy female volunteers received 500 mg tetracycline as a suspension on the fifth day of a 6 day regime of 400 mg cimetidine or placebo, 8 hourly and at bedtime. 500 mg tetracycline as tablets was also given with cimetidine only. 2 Following a single dose of cimetidine the mean peak tetracycline plasma concentration was significantly reduced by 1.2 microgram/ml and the area under the plasma concentration, time curve was decreased by 40%. The 72 h urinary tetracycline excretion was diminished by approximately 30%. 3 Tetracycline had no effect on the plasma concentration, time profile of cimetidine. 4 Administration of 400 mg cimetidine 8 hourly and at night for 6 days and dosing with 500 mg tetracycline as tablets or suspension on the fifth day produced no alteration in tetracycline kinetics. 5 It was concluded that under clinical circumstances it is unlikely that cimetidine produces a clinically significant alteration in tetracycline absorption or disposition. 6 The bioavailability of tetracycline from tablets and suspension was found to be similar (31.2% and 36.9% of the dose excreted in the urine over 72 h). 7 The mean renal clearance of tetracycline was 83.8 ml/min (95% confidence interval +/- 9.2 ml/min) and was unaltered by cimetidine treatment.
mesh_terms: D000328:Adult; D001682:Biological Availability; D002927:Cimetidine / Q000494:pharmacology*; D004347:Drug Interactions; D005260:Female; D006146:Guanidines / Q000494:pharmacology*; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects*; D007700:Kinetics; D013535:Suspensions; D013607:Tablets; D013752:Tetracycline / Q000008:administration & dosage / Q000378:metabolism*; D013997:Time Factors
chemical_list: D006146:Guanidines; D013535:Suspensions; D013607:Tablets; D002927:Cimetidine; D013752:Tetracycline