Syncope caused by nonsteroidal anti-inflammatory drugs and angiotensin-converting enzyme inhibitors.

A 85-year-old woman with diabetes mellitus and prior myocardial infarction was transferred to the emergency room with loss of consciousness due to marked bradycardia caused by hyperkalemia. The T wave during right ventricular pacing was tall and tent-shaped while the concentration of serum potassium was high, and its amplitude during pacing was decreased after correction of the serum potassium level. Simultaneously with the correction, normal sinus rhythm was restored. The cause of hyperkalemia was considered to be several doses of loxoprofen, a nonsteroidal anti-inflammatory drug (NSAID), prescribed for her lumbago by an orthopedic specialist, in addition to the long-term intake of imidapril, an angiotensin-converting enzyme inhibitor (ACEI), prescribed for her hypertension by a cardiologist. This case warns physicians that the combination of NSAID and ACEI can produce serious side effects in aged patients who frequently suffer from hypertension, diabetes mellitus, ischemic heart disease, and degenerative joint disease.