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cardio:diuretics:furosemide [2026/02/15 03:26] – created andrew2393cnscardio:diuretics:furosemide [2026/03/15 17:02] (current) – Create Furosemide page wilkie
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-====== Furosemide (Lasix®) ====== +====== Furosemide (Lasix®) ======<WRAP right 340px><WRAP infobox>| | {{ :cardio:diuretics:furosemide_structure.svg |}} |^ Furosemide || Brand Names | Lasix® || Drug Class | [[cardio:diuretics:loop:start|Loop Diuretic]] || Primary Indications | [[cardio:heart_failure:start|Heart Failure]]; Pulmonary edema; Volume overload; CKD edema || Blood Pressure Effect | ↓ preload, ↓ BP || Mortality Benefit | No (symptom relief) || Elimination | Renal || Black Box Warning | Ototoxicity (high dose/rapid IV) || FDA Approval | 1966 |</WRAP></WRAP>===== Overview =====Furosemide is a potent loop diuretic that blocks NKCC2 in the thick ascending limb, producing brisk natriuresis and diuresis. It is first-line for acute decompensated heart failure and volume overload.<WRAP clear></WRAP>----===== Mechanism of Action =====**Primary Molecular Target**  * Na-K-2Cl cotransporter (NKCC2) in thick ascending limb**Segment Effects**  * ↓ NaCl reabsorption in TAL  * ↑ Ca2+ and Mg2+ excretion  * Disrupts medullary concentrating gradient**Net Physiologic Outcomes**  * Powerful diuresis  * ↓ preload and pulmonary congestion  * Rapid symptom relief in volume overload----===== Indications =====  * Acute pulmonary edema  * Decompensated heart failure  * Edema in CKD/cirrhosis/nephrotic syndrome  * Severe hypertension with volume overload----<WRAP blackbox>===== Black Box Warning =====Risk of profound diuresis, electrolyte depletion, and ototoxicity with high doses or rapid IV administration.</WRAP>----<WRAP contra>===== Contraindications =====Absolute:  * Anuria  * Severe sulfonamide allergy (rare)Relative / Caution:  * Hypovolemia  * Severe electrolyte depletion  * Gout</WRAP>----<WRAP details>===== Dosing =====Heart failure/edema:  * PO: 20–80 mg daily or BID (titrate)  * IV: 20–40 mg, repeat as neededRenal adjustment:  * Higher doses often required in CKD</WRAP>----<WRAP details>===== Pharmacokinetics =====Absorption:  * Oral/IVBioavailability:  * ~50% (variable)Metabolism:  * Minimal hepaticHalf-life:  * ~2 hoursElimination:  * Renal</WRAP>----<WRAP details>===== Adverse Effects =====Common:  * Hypokalemia  * Hypomagnesemia  * Polyuria  * HypotensionSerious:  * Ototoxicity  * AKI from overdiuresis  * Hyponatremia</WRAP>----<WRAP details>===== Drug Interactions =====Increased risk:  * Digoxin toxicity (via hypokalemia)  * NSAIDs (↓ diuretic effect)  * Lithium (↑ levels)Avoid combination:  * Aminoglycosides (ototoxicity risk)</WRAP>----<WRAP monitoring>===== Monitoring =====Labs:  * Electrolytes (K+, Mg2+, Na+)  * CreatinineVitals:  * Blood pressure  * WeightClinical:  * Volume status  * Hearing changes (high dose)</WRAP>----<WRAP pearls>===== Clinical Pearls =====  * Most potent class of diuretics  * Useful in acute pulmonary edema  * Causes hypocalcemia (unlike thiazides)</WRAP>----===== Comparison Within Class =====Compared to other [[cardio:diuretics:loop:start|loop diuretics]]:  * Shorter half-life than torsemide  * Variable oral bioavailability  * Rapid onset when IV----===== Related =====  * [[cardio:diuretics:loop:start|Loop Diuretics]]  * [[cardio:heart_failure:start|Heart Failure]]  * [[cardio:diuretics:start|Diuretics]]
- +
-<WRAP right 340px> +
-<WRAP infobox> +
-^ Furosemide | {{ :cardio:diuretics:furosemide.svg?200 |}} | +
-| Brand Name | Lasix® | +
-| Drug Class | [[cardio:diuretics:start|Loop Diuretic]] | +
-| Primary Indication | Edema, Heart Failure | +
-| Site of Action | Thick Ascending Limb | +
-| Mechanism | Na⁺/K⁺/2Cl⁻ Cotransporter Inhibition | +
-| Potassium Effect | ↓ (Hypokalemia risk) | +
-| Calcium Effect | ↓ Reabsorption | +
-| Bioavailability | Variable (~50%) | +
-| Half-Life | ~1–2 hours | +
-| FDA Approval | 1966 | +
-</WRAP> +
-</WRAP> +
- +
-===== Overview ===== +
- +
-Furosemide is a loop diuretic that inhibits sodium reabsorption in the thick ascending limb of the loop of Henle. +
- +
-It is a potent natriuretic agent used primarily for volume overload states including heart failure, cirrhosis, and renal disease. +
- +
-Loop diuretics remain the cornerstone of acute decompensated heart failure management. +
- +
-<WRAP clear></WRAP> +
- +
----- +
- +
-===== Mechanism of Action ===== +
- +
-**Site of Action** +
-  * Thick ascending limb of the loop of Henle   +
- +
-**Transporter Blocked** +
-  * Na⁺/K⁺/2Cl⁻ cotransporter (NKCC2)   +
- +
-**Physiologic Effects** +
-  * ↑ Sodium and water excretion   +
-  * ↑ Potassium excretion   +
-  * ↑ Calcium excretion   +
-  * ↑ Magnesium excretion   +
-  * Disrupts medullary concentration gradient   +
- +
-Net effect: +
-  * Powerful diuresis   +
-  * Rapid reduction in preload   +
- +
----- +
- +
-===== Indications ===== +
- +
-  * Acute decompensated heart failure   +
-  * Chronic heart failure   +
-  * Pulmonary edema   +
-  * Cirrhosis with ascites   +
-  * Nephrotic syndrome   +
-  * Severe hypertension (adjunct)   +
-  * Hypercalcemia (with IV fluids)   +
- +
-Effective even when eGFR < 30. +
- +
----- +
- +
-<WRAP contra> +
-===== Contraindications ===== +
- +
-Absolute: +
-  * Anuria   +
-  * Severe electrolyte depletion   +
- +
-Relative / Caution: +
-  * Hypotension   +
-  * Dehydration   +
-  * Gout   +
-  * Concomitant nephrotoxic drugs   +
- +
-</WRAP> +
- +
----- +
- +
-<WRAP details> +
-===== Dosing ===== +
- +
-Oral: +
-  * 20–80 mg once or twice daily   +
- +
-IV (acute HF): +
-  * 20–40 mg initial dose   +
-  * Titrate based on response   +
- +
-Higher doses required in renal impairment. +
- +
-Dose-response curve is steep. +
- +
-</WRAP> +
- +
----- +
- +
-<WRAP details> +
-===== Pharmacokinetics ===== +
- +
-Absorption: +
-  * Oral and IV   +
- +
-Bioavailability: +
-  * ~50% (variable)   +
- +
-Half-life: +
-  * ~1–2 hours   +
- +
-Duration: +
-  * 6–8 hours   +
- +
-Elimination: +
-  * Renal   +
- +
-Short duration often requires twice-daily dosing. +
- +
-</WRAP> +
- +
----- +
- +
-<WRAP details> +
-===== Adverse Effects ===== +
- +
-Electrolyte: +
-  * Hypokalemia   +
-  * Hyponatremia   +
-  * Hypomagnesemia   +
-  * Hypocalcemia   +
- +
-Metabolic: +
-  * Hyperuricemia   +
-  * Metabolic alkalosis   +
- +
-Other: +
-  * Ototoxicity (high doses or rapid IV infusion)   +
-  * Hypotension   +
-  * Volume depletion   +
- +
-</WRAP> +
- +
----- +
- +
-<WRAP details> +
-===== Drug Interactions ===== +
- +
-Aminoglycosides: +
-  * ↑ Ototoxicity risk   +
- +
-Lithium: +
-  * ↑ Lithium levels   +
- +
-RAAS inhibitors: +
-  * Additive hypotension   +
- +
-Other diuretics: +
-  * Additive electrolyte abnormalities   +
- +
-</WRAP> +
- +
----- +
- +
-<WRAP monitoring> +
-===== Monitoring ===== +
- +
-  * Weight   +
-  * Urine output   +
-  * Electrolytes (Na⁺, K⁺, Mg²⁺)   +
-  * Renal function   +
-  * Blood pressure   +
- +
-</WRAP> +
- +
----- +
- +
-<WRAP pearls> +
-===== Clinical Pearls ===== +
- +
-  * Most commonly used loop diuretic.   +
-  * Effective in renal impairment.   +
-  * Causes hypokalemia and metabolic alkalosis.   +
-  * IV administration acts within minutes.   +
-  * Ototoxicity risk with high-dose or rapid infusion.   +
-  * Often combined with thiazides for diuretic synergy.   +
- +
-</WRAP> +
- +
----- +
- +
-===== Comparison Within Class ===== +
- +
-Compared to [[cardio:diuretics:chlorthalidone|Chlorthalidone]]: +
-  * More potent   +
-  * Effective in renal failure   +
-  * Shorter duration   +
- +
-Compared to [[cardio:diuretics:torsemide|Torsemide]]: +
-  * Shorter half-life   +
-  * More variable bioavailability   +
- +
-Compared to [[cardio:diuretics:bumetanide|Bumetanide]]: +
-  * Less potent per mg   +
-  * More commonly used   +
- +
----- +
- +
-===== Related ===== +
- +
-  * [[cardio:diuretics:start|Diuretics]] +
-  * [[cardio:heart_failure:start|Heart Failure]] +
-  * [[cardio:diuretics:chlorthalidone|Chlorthalidone]] +
-  * [[cardio:diuretics:spironolactone|Spironolactone]]+
cardio/diuretics/furosemide.1771125989.txt.gz · Last modified: by andrew2393cns