Absorption of two antibacterial drugs, cephalexin and co-trimoxazole, in malabsorption syndromes

Abstract

Plasma concentrations and urinary excretion of cephalexin, trimethoprim and sulphamethoxazole (co-trimoxazole) were measured in normal subjects and in patients with coeliac disease, small bowel diverticulosis, Crohn's disease, cystic fibrosis (cephalexin only) and after administration of cholestyramine

The absorption of cephalexin was improved in coeliac disease diverticulosis and cystic fibrosis. In Crohn's disease the peak plasma level was reduced and delayed

The absorption of both trimethoprim and sulphamethoxazole was increased in all three conditions. However there was a disproportionate increase in the plasma level of trimethoprim in coeliac disease and diverticulosis when compared with that of sulphamethoxazole. In Crohn's disease there was a threefold increase in the peak plasma level of sulphamethoxazole

After cholestyramine administration there was malabsorption of all three drugs