Class Explorer · Cardiovascular
Loop diuretics
Block the Na-K-2Cl cotransporter in the thick ascending limb: the most powerful diuresis the nephron can give.
Members
Also in this class: Bumetanide (predictable oral absorption) · Ethacrynic acid (no sulfonamide group). Full pages arrive as the library grows.
Compare the members
Furosemide
- Oral reliability
- Erratic (10-90%)
- Distinguishing point
- The default; IV when gut is congested
Shared across the class
- Indications
- Congestion in HF · Edema states · Hypertension in advanced CKD
- Adverse effects
- Hypokalemia, hypomagnesemia · Volume depletion and AKI · Hyponatremia · Ototoxicity (high dose IV) · Gout
- Contraindications
- Anuria unresponsive to trial
- Monitoring
- Daily weight in active diuresis · Electrolytes and creatinine within days of changes · Symptoms of congestion vs depletion
What makes each agent different
- Furosemide's oral absorption is erratic (10-90%); bumetanide's is reliable: the classic switch when oral response disappoints.
- Ethacrynic acid is the refuge for true severe sulfonamide allergy.
Loops are threshold drugs: double the ineffective dose rather than repeating it.
Last reviewed 2026-08-15 · Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed.