Decreased tetracycline bioavailability caused by a bismuth subsalicylate antidiarrheal mixture.
Oral coadministration of a single 250-mg tetracycline capsule and 60 ml of a bismuth subsalicylate antidiarrheal mixture reduced tetracycline absorption by 34% without appearing to perturb its absorption or disposition rate. A pronounced increase in intersubject tetracycline absorption variability also was noted. Apparently, the reduction in tetracycline bioavailability previously reported with a kaolin-pectin suspension is not peculiar to kaolin-pectin but can be expected with almost any antidiarrheal whose mechanism of action is adsorptive in nature.
D000328:Adult; D000930:Antidiarrheals / Q000494:pharmacology*; D001682:Biological Availability; D001729:Bismuth / Q000494:pharmacology*; D004347:Drug Interactions; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects; D012459:Salicylates / Q000494:pharmacology; D013752:Tetracycline / Q000378:metabolism*
D000930:Antidiarrheals; D012459:Salicylates; D013752:Tetracycline; D001729:Bismuth