Ethacrynic acid
Indications
Ethacrynic acid is used for:
Oedema, Acute pulmonary oedema
Adult Dose
Oral
Oedema
Adult: Initially, 50 mg in the morning, increase if necessary, by 25-50 mg increments daily to min effective dose. Usual effective range: 50-200 mg daily. Severe cases: Up to 400 mg daily. Doses >50 mg should be given in divided doses.
Child: >2 yr Initially, 25 mg daily, increase cautiously if necessary, by 25 mg daily.
Intravenous
Acute pulmonary oedema
Adult: As Na etacrynate: Usual dose: 50 mg or 0.5-1 mg/kg via slow IV inj or infusion over 10 min; a 2nd dose may be given, if required, at a new inj site. Max: 100 mg
Child Dose
Congenital Heart Disease, Nephrotic Syndrome
PO: 1 mg/kg/dose qDay; may increase q2-3days to maximum of 3 mg/kg/day
IV: Data limited; 1 mg/kg IV
Renal Dose
Renal Impairment
Not necessary to supplement dose; not removed by hemo- or peritoneal dialysis
CrCl <10 mL/minute: Not recommended
Administration
IV Administration
Do not give SC or IM due to local pain & irritation
Single doses should not exceed 100 mg
Administer IVP at 10 mg/min
If second dose needed, a new injection site is recommended to avoid possible thrombophlebitis
Contra Indications
Anuria, history of severe watery diarrhoea. Infants.
Precautions
Patient w/ advanced hepatic cirrhosis, electrolyte imbalance, hepatic encephalopathy, severe myocardial disease and those undergoing surgery. Renal impairment. Childn. Pregnancy and lactation. Monitoring Parameters Monitor BP, renal function, serum electrolytes, CO2, BUN, fluid status including input and output, wt, hearing.
Pregnancy-Lactation
Pregnancy Category: B
Lactation: excretion in milk unknown/not recommended
Interactions
May increase the ototoxicity and nephrotoxicity of aminoglycoside antibiotics and some cephalosporins. May increase risk of GI bleeding when used w/ other gastric irritants, corticosteroids, anticoagulants. May cause orthostatic hypotension when used w/ other antihypertensive agents. Displaces warfarin from plasma protein. May increase risk of lithium toxicity. Decreased therapeutic effect w/ NSAIDs.
May interfere w/ the hypoglycaemic effect of insulin or other antidiabetic agents. May potentiate kaliuresis and natriuretic effect of acetazolamide, dichlorphenamide, methazolamide.
Adverse Effects
Side effects of Ethacrynic acid :
Frequency Not Defined
Injection site reaction
Hyperuricemia
Gout
Hypotension
Hypokalemia
Electrolyte abnormalities
Hyperglycemia/hypoglycemia
Hyperlipidemia
Ototoxicity
Tinnitus
Photosensitivity
Muscle cramps
Dizziness
Confusion
Headache
Nausea/vomiting
Anorexia
Dysphagia
Diarrhea
Pancreatitis
Agranulocytosis
Neutropenia
Thrombocytopenia
Hematuria
Mechanism of Action
Etacrynic acid is a loop diuretic that binds w/ sulfhydryl groups of renal cellular proteins. It inhibits the reabsorption of Na and Cl in the ascending loop of Henle and distal renal tubules, interfering w/ the Cl-binding cotransport system, hence excretion of Na, K, Ca, Mg, and Cl ions are increased and water excretion enhanced.