Class: Loop Diuretic
Dosage Forms. Tablet: 20 mg, 40 mg, 80 mg; Solution: 40 mg/5 mL, 10 mg/mL
Common FDA Label Indication, Dosing, and Titration.
1. Edema related to CHF, renal failure: Adults: initial 20-40 mg po daily; titrate to maintenance dose (max 600 mg/d). Premature neonates (<29 wk): 1-2 mg/kg/dose po daily, may increase to 6 mg/kg/dose; (>29 wk): 1-2 mg/kg/dose po 1-2 times per day, may increase to 6 mg/kg/dose. Neonates: 1-3 mg/kg po q8h as needed. Infants and children: initial, 2 mg/kg/dose po, titrate to maintenance dose (max 6 mg/kg/dose)
2. Hypertension: Adults: initial 12.5-25 mg po daily, titrate to maintenance dose 50-100 mg po daily or in divided doses; Children: 1-2 mg/kg po daily in single or divided doses, infants <6 mo old may require doses up to 3 mg/kg po daily in 2 divided doses; Infants <2 y old, max dose 37.5 mg/d; Children 2-12 y old, max dose 100 mg/d
Off-Label Uses. None
MOA. Furosemide is a loop diuretic that is actively secreted via the nonspecific organic acid transport system into the lumen of the thick ascending limb of Henle’s loop, where it decreases sodium reabsorption by competing for the chloride site on the Na+-K+-2Cl- cotransporter.
Drug Characteristics: Furosemide
Medication Safety Issues: Furosemide
Drug Interactions: Furosemide
Adverse Reactions: Furosemide
Efficacy Monitoring Parameters. Decreased blood pressure, increased urine output, reduction in edema, daily weights. For treating renal failure, increase in urine volume, creatinine clearance, blood urea nitrogen, and electrolytes.
Toxicity Monitoring Parameters. Severe volume depletion can occur. Monitor serum and urine electrolytes, uric acid, and blood glucose at baseline and every 3-6 mo after therapy. Audiometric test (if ototoxicity suspected).
Key Patient Counseling Points. Avoid alcohol and NSAIDs. Increased risk of sun sensitivity, use sunscreen and avoid tanning. Avoid activities requiring coordination until drug effects are realized, as drug may cause dizziness, vertigo, or blurred vision. Report signs/symptoms of hypotension, decreased urine output, or ototoxicity; severe skin reactions. Eat high-potassium foods, as directed by healthcare professional.
Clinical Pearls. Drug of first choice for edema and hypertension.