💊 Furosemide

Loop Diuretic

Generic Name	Furosemide
Drug Class	Loop Diuretic
Indications	Edema due to heart failure, liver cirrhosis, or renal disease Hypertension (resistant cases) Acute pulmonary edema Hypercalcemia
Mechanism of Action	Inhibits Na⁺/K⁺/2Cl⁻ symporter in the thick ascending limb of the loop of Henle → increased excretion of Na⁺, Cl⁻, K⁺, and water.
Available Forms & Strengths	• Tablet: 20 mg, 40 mg, 80 mg • Oral solution: 10 mg/mL • IV / IM injection: 10 mg/mL
Dosage	Adults (oral): 20–80 mg once daily or divided doses IV (emergency): 20–40 mg; may repeat Children: 1 mg/kg per dose; max 6 mg/kg/day
Route	Oral, IV, IM
Common Side Effects	Hypokalemia Hypomagnesemia Dehydration Hypotension Dizziness
Serious Adverse Effects	Ototoxicity (high IV doses), electrolyte disturbances, renal impairment, hyperuricemia
Contraindications	• Anuria • Severe electrolyte depletion • Hypersensitivity to furosemide
Precautions	• Hepatic disease • Renal impairment • Diabetes (may ↑ glucose) • Elderly (risk of hypotension)
Drug Interactions	• Other diuretics • ACE inhibitors (↑ hypotension risk) • Aminoglycosides (↑ ototoxicity) • Digoxin (↑ arrhythmia risk with hypokalemia)
Pregnancy & Lactation	Pregnancy: Use only if clearly needed Lactation: Excreted in breast milk; caution advised
Storage	Store below 30°C, protect from light
References	BNF \| BNF for Children \| Goodman & Gilman

⚠️ Clinical note: Monitor electrolytes (K⁺, Mg²⁺, Na⁺) and renal function during therapy. Adjust dose in renal impairment.