Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ETHACRYNIC ACID vs ETHACRYNATE SODIUM
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Inhibits sodium-potassium-chloride cotransporter (NKCC2) in the thick ascending limb of the loop of Henle, leading to increased excretion of sodium, chloride, potassium, and water. Also inhibits prostaglandin degradation.
Ethacrynate sodium inhibits the Na-K-2Cl cotransporter (NKCC2) in the thick ascending limb of the loop of Henle, reducing reabsorption of sodium, chloride, and potassium, leading to increased diuresis.
Treatment of edema associated with congestive heart failure, cirrhosis, and renal disease,Treatment of ascites,Treatment of hypertension (off-label),Adjunctive therapy in acute pulmonary edema (off-label)
Treatment of edema associated with congestive heart failure, hepatic cirrhosis, and renal disease,Short-term management of ascites due to malignancy, idiopathic edema, and lymphedema,Off-label: Adjunct in treatment of acute hypercalcemia
50 to 100 mg orally once daily; may increase by 25 to 50 mg increments at intervals of 2 to 3 days up to 400 mg/day. IV: 0.5 to 1 mg/kg slowly (over several minutes); usual initial dose 50 mg.
50 mg intravenously once daily; may increase in increments of 25-50 mg as needed, maximum 200 mg/day.
Terminal elimination half-life is approximately 2-4 hours in patients with normal renal function; may be prolonged in renal impairment.
Terminal elimination half-life: 2-4 hours in normal renal function; prolonged to 20-30 hours in end-stage renal disease.
Primarily metabolized by conjugation with glutathione; also undergoes hepatic metabolism via CYP450 enzymes (minor).
Primarily metabolized by hepatic glutathione S-transferase (GST) to a cysteine conjugate; minor metabolism via oxidation. Excreted in urine and bile.
Primarily renal (approximately 60-70% as unchanged drug and metabolites) with some biliary/fecal excretion (approximately 30-40%).
Renal: approximately 30% unchanged; biliary/fecal: minor (less than 10%); majority metabolized to cysteine adducts excreted in urine.
Approximately 90-98% bound to plasma proteins, primarily albumin.
Approximately 95% bound, primarily to albumin.
Volume of distribution is approximately 0.1-0.2 L/kg, indicating limited extravascular distribution.
0.1-0.2 L/kg (small Vd, consistent with high protein binding and limited extravascular distribution).
Oral bioavailability is approximately 100%.
Oral: approximately 100% (well absorbed, no significant first-pass metabolism).
e GFR 30-59 m L/min: no adjustment; e GFR <30 m L/min: avoid use due to risk of ototoxicity and decreased efficacy.
e GFR 30-59 m L/min: reduce dose by 50%; e GFR <30 m L/min: avoid use or use with extreme caution.
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: avoid use.
Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce dose by 50%; Child-Pugh Class C: avoid use.
Oral: 1 mg/kg/dose once daily; may increase by 1 mg/kg/dose at intervals of 2-3 days up to 3 mg/kg/day. IV: 1 mg/kg/dose slow IV; maximum 50 mg/dose.
1 mg/kg intravenously once daily; maximum 50 mg/day. Not recommended in neonates.
Initiate at lower doses (25 mg orally once daily) due to increased risk of electrolyte disturbances and renal impairment; monitor closely.
Start at 25 mg intravenously once daily; increase slowly due to increased risk of electrolyte disturbances and hypotension.
This drug is a potent diuretic which, if given in excessive amounts, can lead to profound diuresis with water and electrolyte depletion. Close medical supervision and dose adjustment are required.
Ethacrynic acid (ethacrynate) can cause profound diuresis with water and electrolyte depletion; close medical supervision and dose titration are required.
Risk of excessive diuresis leading to dehydration, electrolyte imbalance, and hypovolemia,May cause ototoxicity, especially with rapid IV administration or in patients with renal impairment,Can worsen azotemia or precipitate hepatic encephalopathy in cirrhotic patients,Monitor serum electrolytes, CO2, BUN, and creatinine regularly,Use with caution in patients with diabetes mellitus (may increase blood glucose),May cause hyperuricemia and gout
May cause severe electrolyte disturbances (hypokalemia, hyponatremia, hypochloremia) and volume depletion,Ototoxicity, especially with rapid IV administration or in patients with renal impairment; may be irreversible,Hyperuricemia and gout,Hepatic coma can be precipitated in patients with cirrhosis or ascites,May increase risk of digoxin toxicity due to hypokalemia,Photosensitivity reaction possible
Anuria,Hypersensitivity to ethacrynic acid or any component of the formulation,Severe electrolyte depletion (hypokalemia, hyponatremia) until corrected,Concurrent use with other ototoxic drugs (e.g., aminoglycosides) may increase risk
Anuria,Hypersensitivity to ethacrynic acid or any component,Severe electrolyte depletion (hypokalemia, hyponatremia, hypochloremia),Hepatic coma or precoma
Avoid licorice, which can worsen hypokalemia. Limit salt intake as directed. No specific food interactions; maintain a balanced diet.
Avoid excessive intake of salt substitutes containing potassium unless advised by your doctor. Grapefruit juice may enhance diuretic effect; monitor for hypotension. Alcohol can increase diuretic effect and risk of hypotension. Caffeine may worsen electrolyte imbalance. Ensure adequate fluid intake unless fluid restriction is prescribed.
First trimester: Limited human data; animal studies show no teratogenicity but fetal toxicity at high doses. Second trimester: Theoretical risk of electrolyte imbalances affecting fetal development. Third trimester: Risk of premature ductus arteriosus closure due to prostaglandin inhibition (theoretical), neonatal ototoxicity, and thrombocytopenia.
Ethacrynate sodium crosses the placenta. First trimester: Limited human data; animal studies not available. Second and third trimesters: Potential for electrolyte disturbances, ototoxicity, and oligohydramnios in the fetus due to diuretic effect. Avoid use in pregnancy unless clearly needed.
Safety not established. Drug excreted in breast milk; M/P ratio unknown. Avoid breastfeeding or use with caution due to potential for ototoxicity and electrolyte disturbances in the infant.
Excreted into breast milk in low concentrations; M/P ratio not determined. Potential for adverse effects in nursing infants (e.g., electrolyte imbalance, diuresis). Weigh benefits against risks; consider alternative diuretics.
No standard dose adjustment; use lowest effective dose. Monitor for hypokalemia and volume depletion, which may be more pronounced in pregnancy. Consider adjusting dose based on maternal weight and renal function.
Pregnancy may alter pharmacokinetics due to increased plasma volume and renal clearance; however, specific dose adjustments for ethacrynate sodium are not established. Use lowest effective dose and monitor for hypotension and electrolyte imbalances.
Ethacrynic acid is a loop diuretic used for patients with sulfonamide allergy, as it is not a sulfonamide derivative. Monitor for ototoxicity, especially when given with aminoglycosides or in renal impairment. Rapid diuresis may cause hypokalemia, hypomagnesemia, and metabolic alkalosis. Use cautiously in hepatic cirrhosis to avoid electrolyte-induced coma.
Ethacrynate sodium is a loop diuretic used for patients with sulfonamide allergy as it is not a sulfonamide derivative. Monitor for ototoxicity, especially in patients with renal impairment or when used with other ototoxic drugs. Rapid IV administration can cause severe hypotension; infuse slowly over several minutes. Hypokalemia and hypomagnesemia are common; monitor electrolytes and consider potassium-sparing diuretic or supplementation. Ethacrynic acid can cause GI bleeding; use with caution in peptic ulcer disease.
Take exactly as prescribed, usually once or twice daily.,Expect increased urination; take in the morning to avoid nighttime trips.,Weigh yourself daily and report rapid weight gain or loss.,Avoid alcohol and medications that may cause dizziness.,This drug may cause hearing loss or ringing in the ears; report immediately.,Do not take with aspirin or other NSAIDs without doctor approval.,Inform your doctor if you have gout, diabetes, or kidney disease.,Stay adequately hydrated but avoid excessive fluid intake.
Take this medication exactly as prescribed, usually once or twice daily.,You may need to urinate frequently; take your last dose of the day early to avoid nighttime urination.,Avoid alcohol and limit salt intake to help reduce fluid retention.,Report any hearing loss, ringing in the ears, or dizziness to your healthcare provider immediately.,Eat potassium-rich foods like bananas, oranges, or potatoes unless directed otherwise by your doctor.,Weigh yourself daily and report sudden weight gain or loss to your healthcare provider.,Do not take any over-the-counter medications, especially NSAIDs, without consulting your doctor.,If you miss a dose, take it as soon as you remember unless it is almost time for the next dose. Do not double the dose.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ETHACRYNIC ACID vs ETHACRYNATE SODIUM, answered by our medical review team.
ETHACRYNIC ACID is a Loop Diuretic that works by Inhibits sodium-potassium-chloride cotransporter (NKCC2) in the thick ascending limb of the loop of Henle, leading to increased excretion of sodium, chloride, potassium, and water. Also inhibits prostaglandin degradation.. ETHACRYNATE SODIUM is a Loop Diuretic that works by Ethacrynate sodium inhibits the Na-K-2Cl cotransporter (NKCC2) in the thick ascending limb of the loop of Henle, reducing reabsorption of sodium, chloride, and potassium, leading to increased diuresis.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ETHACRYNIC ACID and ETHACRYNATE SODIUM depend on the specific clinical indication. These are both Loop Diuretic agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of ETHACRYNIC ACID is: 50 to 100 mg orally once daily; may increase by 25 to 50 mg increments at intervals of 2 to 3 days up to 400 mg/day. IV: 0.5 to 1 mg/kg slowly (over several minutes); usual initial dose 50 mg.. The standard adult dose of ETHACRYNATE SODIUM is: 50 mg intravenously once daily; may increase in increments of 25-50 mg as needed, maximum 200 mg/day.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between ETHACRYNIC ACID and ETHACRYNATE SODIUM in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. ETHACRYNIC ACID is classified as Category C. First trimester: Limited human data; animal studies show no teratogenicity but fetal toxicity at high doses. Second trimester: Theoretical risk of electrolyte imbalances affecting . ETHACRYNATE SODIUM is classified as Category C. Ethacrynate sodium crosses the placenta. First trimester: Limited human data; animal studies not available. Second and third trimesters: Potential for electrolyte disturbances, oto. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.