Possible interaction between cyclosporine and glibenclamide in posttransplant diabetic patients

The possible occurrence of a kinetic interaction between cyclosporine A and glibenclamide was assessed by reviewing data of six posttransplant diabetic patients who received the two drugs concurrently. Coadministration of the two drugs resulted in a 57% increase in the steady-state plasma cyclosporine levels despite normal hepatic and renal functions in the patients. This elevation in cyclosporine level is possibly due to an interaction between the two drugs resulting from an inhibition of CYP3A4-mediated metabolism of cyclosporine by glibenclamide. This observation calls for a closer monitoring of cyclosporine plasma levels during concomitant administration of these two drugs in this group of patients.