furosemid

Furosemide, also known as furosemid in some languages, is a potent loop diuretic used to reduce fluid overload in conditions such as heart failure, liver cirrhosis, and nephrotic syndrome. It is also employed to treat edema and to manage acute pulmonary edema or certain hypertensive urgencies when rapid diuresis is needed. It can be administered orally or by injection.

Mechanism of action: Furosemide inhibits the Na+-K+-2Cl− cotransporter (NKCC2) in the thick ascending limb of the loop of Henle, decreasing reabsorption of sodium and chloride. This leads to increased excretion of water, sodium, chloride, potassium, calcium, and magnesium. The drug may also cause venodilation, contributing to a decrease in preload.

Pharmacokinetics: Absorption from the gastrointestinal tract is variable when taken orally. Onset of diuresis typically occurs within 30–60 minutes after oral dosing and within minutes after intravenous dosing; duration is about 2–4 hours (oral effects can last longer). Furosemide is primarily eliminated by the kidneys and binds strongly to plasma proteins.

Dosing and monitoring: Initial oral doses commonly range from 20–40 mg once or twice daily, with higher doses used for edema resistance. Maximum daily doses can exceed 600 mg, adjusted for renal function. Electrolyte levels, volume status, and blood pressure should be monitored to guide therapy and prevent complications.

Adverse effects and safety: Common adverse effects include dehydration and electrolyte disturbances such as hypokalemia, hyponatremia, and hypochloremic alkalosis. Ototoxicity is possible with high-dose or rapid IV administration. Hypotension, rash, and photosensitivity may also occur; caution in patients with gout or significant renal impairment.

Interactions and contraindications: NSAIDs can reduce diuretic efficacy. Co-administration with aminoglycosides or other ototoxics increases hearing loss risk. Lithium and certain antihypertensives may interact adversely. Furosemide is contraindicated in anuria and in settings of severe hypovolemia; use with caution in pregnancy.