Potent CYP3A4 inhibitors (ie, ketoconazole, itraconazole, ritonavir, clarithromycin) could alter pharmacokinetics of sitagliptin in patients w/ severe renal impairment or ESRD. OAT3 mediated transport of sitagliptin was inhibited
in vitro by probenecid. Small effect on plasma digoxin conc; monitor patients at risk of digoxin toxicity. Sitagliptin may be a mild inhibitor of P-gp
in vivo.