May lead to loss of glycemic control w/ drugs tend to produce hyperglycemia eg, thiazides & other diuretics, corticosteroids, phenothiazines, thyroid products, estrogens, OCs, phenytoin, nicotinic acid, sympathomimetics, Ca channel blocking drugs & INH. Sitagliptin: Increased AUC & Cmax
w/ cyclosporine (a potent probe inhibitor of p-glycoprotein). Metformin HCl: Increased plasma & blood Cmax
& blood AUC w/ furosemide. Increased plasma Cmax
& AUC & increased amount excreted in the urine w/ nifedipine. Increased systemic exposure & risk for lactic acidosis w/ concomitant use of drugs that interfere w/ common renal tubular transport system (eg, organic cationic transporter-2 [OCT2]/multidrug & toxin extrusion [MATE] inhibitors eg, ranolazine, vandetanib, dolutegravir & cimetidine).