MS-1739

A 76-year-old woman is being reviewed for her medications on the geriatrics ward. She has a medical history of left ventricular failure, atrial fibrillation, gout, left-sided hemianopia, hyperthyroidism, and renal colic. The medications she is taking include ramipril, atenolol, digoxin, allopurinol, warfarin, carbamazepine, and diclofenac. Can you identify which of her medications is classified as a narrow therapeutic index (NTI) drug?