Abstract
The influence of an antidiarrhoeal mixture, Kaopectate(R), on the bioavailability of tetracycline was studied in healthy human subjects. Employing a cross-over design, four subjects in the fasting state were given 250 mg tetracycline HCl as a solution with and without 30 ml Kaopectate(R). A drastic and significant decrease (about 50%) in drug absorption resulted. When the antidiarrhoeal mixture was coadministered with a 250 mg capsule, employing a latin-square design with seven subjects, a similar decrease in absorption was observed. The administration of Kaopectate(R) 2 h before and 2 h after the drug resulted in about 20% decrease in drug absorption.