Moderate
furosemide × hydrochlorothiazide
Loop diuretics×Thiazide diuretics
Mechanism
Sequential nephron blockade: furosemide acts in the loop of Henle, the thiazide in the distal tubule. Additive diuresis in furosemide-resistant HF. Risk of severe dehydration, hypokalemia, hyponatremia, hypomagnesemia, and prerenal azotemia.
Management
Use short term (3–7 days) in patients with resistant HF. Monitor electrolytes, creatinine, and body weight daily in inpatients. Supplement with potassium and/or add spironolactone.
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