enalapril × furosemide

In patients with activated RAAS (significant hypovolemia from aggressive diuresis, severe HF), the first ACE-inhibitor dose can cause an abrupt BP drop with syncope and acute kidney injury. With chronic use, the combination provides synergistic antihypertensive effect.

Before starting an ACE inhibitor, assess volume status and, where possible, hold or reduce furosemide for 24–48 hours. Begin enalapril at the lowest dose (2.5 mg) at night while the patient is recumbent. Check BP, creatinine, and potassium at 3–7 days.