Ethacrynic Acid (Ethacrynate)

A to Z Drug Facts

 Action Inhibits reabsorption of sodium and chloride in proximal and distal tubules and in loop of Henle.

 Indications Treatment of edema associated with CHF, hepatic cirrhosis or renal disease; treatment of ascites, congenital heart disease, nephrotic syndrome. Unlabeled use(s) Treatment of glaucoma; treatment of nephrogenic diabetes insipidus, hypercalcemia.

 Contraindications Anuria; infants; increasing azotemia; severe diarrhea; dehydration; electrolyte imbalance; hypotension.

 Route/Dosage

ADULTS: PO 50–200 mg qd. IV 50 mg (0.5 to 1 mg/kg) qd. CHILDREN: PO 25 mg qd.

 Interactions

Aminoglycosides: May increase auditory toxicity. Cisplatin: May cause additive ototoxicity. Digitalis glycosides: Electrolyte disturbances may predispose to digitalis-induced atrial and ventricular arrhythmias. Lithium: May increase plasma lithium levels and toxicity. Nonsteroidal anti-inflammatory drugs: May decrease effects of ethacrynic acid. Salicylates: May impair diuretic response in patients with cirrhosis and ascites. Thiazide diuretics: Synergistic effects may result in profound diuresis and serious electrolyte abnormalities.

 Lab Test Interferences None well documented.

 Adverse Reactions

CV: Orthostatic hypotension; emboli. CNS: Apprehension; confusion; fatigue; malaise; vertigo; headache; dysphagia. DERM: Rash EENT: Blurred vision; sense of ear fullness; tinnitus; hearing loss. GI: Anorexia; nausea; vomiting; diarrhea; pancreatitis; discomfort; pain; sudden watery, profuse diarrhea; bleeding. GU: Hematuria. HEMA: Neutropenia; thrombocytopenia; agranulocytosis; hyponatremia; hypokalemia; hypomagnesemia; hypocalcemia; hypercalciuria; hypovolemia. HEPA: Jaundice; abnormal LFTs. META: Acute gout; hyperuricemia; hyperglycemia. OTHER: Fever; chills; local irritation and pain with parenteral administration.

 Precautions

Pregnancy: Category B. Lactation: Undetermined. Children: Safety and efficacy not established in infants (see Contraindications) and in children (IV). Dehydration: Excessive diuresis may cause dehydration and decreased blood volume with circulatory collapse and possible vascular thrombosis and embolism, especially in elderly. Electrolyte imbalance: May be more likely in patients receiving large doses with restricted salt intake. Hepatic cirrhosis and ascites: Sudden alterations of electrolyte balance may precipitate hepatic encephalopathy and coma. Ototoxicity: Associated with rapid injection, very large doses or concurrent use of other ototoxic drugs. Photosensitivity: May occur. Systemic lupus erythematosus: May be exacerbated or activated.

 Administration/Storage

• Administer drug PO or IV only. SC or IM injection causes local pain and irritation.
• To prepare IV solution, add 50 ml of D5W or normal saline. If solution is hazy or opalescent, do not use.
• For IV dose, administer drug slowly. Rotate injection sites to avoid thrombophlebitis.
• Discard reconstituted solution if not used within 24 hr.
• Do not administer drug with other drugs or with blood products.
• Do not give with other ototoxic drugs.
• Give oral medication after meal or with food to prevent GI upset.
• Avoid administering within 6 to 8 hr of bedtime to avoid nocturia.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies.
• Obtain baseline BUN, creatinine, potassium and sodium chloride and monitor daily.
• Closely monitor blood glucose.
• Monitor I&O and obtain daily weight.
• Assess patient for signs of GI bleeding.
• Monitor CBC and differential daily.
• Obtain BP and pulse before and during treatment, observing for orthostatic hypotension.
• Assess neurologic status prior to administering drug and during treatment.
• If severe, watery diarrhea occurs, report to physician.
• If signs of ototoxicity (ear fullness, tinnitus, vertigo, hearing loss) occur, slow rate of IV injection.
• If patient develops anuria, hematuria, increases in BUN or creatinine or significant changes in electrolytes, report to physician.
• If signs of dehydration develop (hypotension, tachycardia, postural hypotension, rapid weight loss, decreased filling pressures), notify physician.
• If patient shows change in LOC or mentation, notify physician.
• If patient is elderly or debilitated, observe for possible dehydration.

 Patient/Family Education

• Tell patient to take drug with food or milk.
• Instruct patient to take drug in morning.
• Advise patient to avoid exposure to sunlight or UV light and to use sunscreen or wear protective clothing to avoid photosensitivity reaction.
• Caution patient to avoid sudden position changes to prevent orthostatic hypotension.
• Instruct patient to report these symptoms to physician: confusion or mood changes, increased thirst, dizziness, irregular heart beat, weakness or increased tiredness, diarrhea, blood in urine or stool, muscle weakness or cramps, sudden joint pain or any changes in hearing.
• Advise patients with diabetes mellitus to monitor blood glucose levels closely.

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Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts