Absence of a significant pharmacokinetic interaction between hydrochlorothiazide and triamterene when coadministered.
Hydrochlorothiazide, triamterene, and hydroxytriamterene sulfate were monitored in the plasma and urine of 24 healthy young men taking single doses of a liquid preparation containing both hydrochlorothiazide and triamterene, liquid preparations containing either of these drugs alone, and a combination tablet recently formulated with a dose ratio of hydrochlorothiazide : triamterene (1 : 1.5) found to give optimal potassium-sparing effect. In contradiction to a recent publication, no interaction between the drugs affecting the bioavailability or renal clearance of either could be demonstrated. The previous report of drug-drug interaction probably arose from formulation-related problems with bioavailability from the two capsule and two tablet products which had been studied. A well-formulated hydrochlorothiazide-triamterene combination tablet promotes plasma concentrations and urinary excretion of hydrochlorothiazide, triamterene, and hydroxytriamterene sulfate which are virtually identical to those seen after either a combination liquid dosage form or simple liquid forms containing only one of the two drugs.
D000328:Adult; D001682:Biological Availability; D004338:Drug Combinations; D004347:Drug Interactions; D006801:Humans; D006852:Hydrochlorothiazide / Q000008:administration & dosage / Q000378:metabolism* / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D011485:Protein Binding; D014223:Triamterene / Q000008:administration & dosage / Q000378:metabolism* / Q000494:pharmacology
D004338:Drug Combinations; D006852:Hydrochlorothiazide; D014223:Triamterene