Evaluation of Pharmacokinetic Interactions Between Vildagliptin and Digoxin in Healthy Volunteers

Vildagliptin is a novel antidiabetic agent that is an orally active, potent, and selective inhibitor of dipeptidyl peptidase IV, the enzyme responsible for degradation of the incretin hormones. This open-label, randomized, 3-period crossover study investigated the potential for pharmacokinetic interactions in 18 healthy subjects during coadministration of vildagliptin and digoxin. Subjects were randomized to receive each of 3 treatments: vildagliptin 100 mg qd, digoxin (0.5 mg, then 0.25 mg qd on days 2-7), and the combination vildagliptin/digoxin for 7 days. Coadministration of digoxin with vildagliptin had no effect on exposure to vildagliptin (geometric mean ratios [90% confidence interval]: AUC(0-24h), 0.99 [0.95-1.03]; C(max), 0.95 [0.85-1.06]) or to digoxin (AUC(0-24h), 1.02 [0.94-1.12]; C(max), 1.08 [0.97-1.20]). In addition, no changes in t(max), t((1/2)), and CL/F were observed for either drug. These results indicate that no dose adjustment is necessary when vildagliptin and digoxin are coadministered.