Major
furosemide × losartan
Loop diuretics×Angiotensin II receptor blockers (sartans)
Mechanism
Same as the ACE-inhibitor/furosemide pair: in a hypovolemic patient the first sartan dose can cause an abrupt BP drop and acute kidney injury. Chronic combination provides synergistic BP reduction.
Management
Assess volume status before starting losartan. Start at 25–50 mg at night. Check BP, creatinine, and potassium at 3–7 days. In older patients, start at 25 mg.
Sources
- Lexicomp: Lexicomp Drug Interactions (2024)— Wolters Kluwer Clinical Drug Information, Inc. Lexi-Interact Online, 2024
- Pharmaceutical Press: Stockley's Drug Interactions, 12th edition (2024)— Preston CL (ed.). Stockley's Drug Interactions. 12th ed. London: Pharmaceutical Press; 2024