Furosemide

Provider Level

RN/Paramedic

Class

Loop diuretic

Mechanism of Action

Inhibits reabsorption of sodium and chloride in the ascending loop of Henle and distal renal tubules. Induces profound diuresis and mild venous vasodilation which decreases cardiac preload.

Indications

Acute pulmonary edema associated with congestive heart failure.

Contraindications

Anuria, severe hypovolemia, severe electrolyte depletion (especially hypokalemia), and hypersensitivity.

Routes

IV, IO, IM, PO

Onset / Duration

Onset: 5 minutes (IV). Peak: 30 minutes. Duration: 2 hours.

Adverse Effects

Hypotension, hypokalemia, hyponatremia, dehydration, arrhythmias (due to electrolyte shifts), and tinnitus/ototoxicity (with rapid IV administration).

Precautions & Interactions

Monitor blood pressure closely as it may cause profound hypotension. Use caution in patients with severe sulfonamide allergies. Protect medication from light.

Special Considerations

Venous pooling and preload reduction typically occur before the onset of diuresis. Administer IV push slowly to minimize the risk of transient or permanent hearing loss.