Ethacrynic acid

Ethacrynic acid is indicated for treatment of edema when an agent with greater diuretic potential than those commonly employed is required. 1. Treatment of the edema associated with congestive heart failure, cirrhosis of the liver, and renal disease, including the nephrotic syndrome. 2. Short-term management of ascites due to malignancy, idiopathic edema, and lymphedema. 3. Short-term management of hospitalized pediatric patients, other than infants, with congenital heart disease or the nephrotic syndrome. 4. Intravenous ethacrynate sodium is indicated when a rapid onset of diuresis is desired, e.g., in acute pulmonary edema, or when gastrointestinal absorption is impaired or oral medication is not practicable.

Dosage must be regulated carefully to prevent a more rapid or substantial loss of fluid or electrolyte than is indicated or necessary. The magnitude of diuresis and natriuresis is largely dependent on the degree of fluid accumulation present in the patient. Similarly, the extent of potassium excretion is determined in large measure by the presence and magnitude of aldosteronism. Oral Use Ethacrynic acid is available for oral use as 25 mg tablets. Dosage: To Initiate Diuresis In Adults: The smallest dose required to produce gradual weight loss (about 1 to 2 pounds per day) is recommended. Onset of diuresis usually occurs at 50 to 100 mg for adults. After diuresis has been achieved, the minimally effective dose (usually from 50 to 200 mg daily) may be given on a continuous or intermittent dosage schedule.

All diuretics, including ethacrynic acid, are contraindicated in anuria. If increasing electrolyte imbalance, azotemia, and/or oliguria occur during treatment of severe, progressive renal disease, the diuretic should be discontinued. In a few patients this diuretic has produced severe, watery diarrhea. If this occurs, it should be discontinued and not used again. Until further experience in infants is accumulated, therapy with oral and parenteral ethacrynic acid is contraindicated. Hypersensitivity to any component of this product.

The effects of ethacrynic acid on electrolytes are related to its renal pharmacologic activity and are dose dependent. The possibility of profound electrolyte and water loss may be avoided by weighing the patient throughout the treatment period, by careful adjustment of dosage, by initiating treatment with small doses, and by using the drug on an intermittent schedule when possible. When excessive diuresis occurs, the drug should be withdrawn until homeostasis is restored. When excessive electrolyte loss occurs, the dosage should be reduced or the drug temporarily withdrawn. Initiation of diuretic therapy with ethacrynic acid in the cirrhotic patient with ascites is best carried out in the hospital. When maintenance therapy has been established, the individual can be satisfactorily followed as an outpatient.

Gastrointestinal Anorexia, malaise, abdominal discomfort or pain, dysphagia, nausea, vomiting, and diarrhea have occurred. These are more frequent with large doses or after one to three months of continuous therapy. A few patients have had sudden onset of profuse, watery diarrhea. Discontinue ethacrynic acid if diarrhea is severe and do not give it again. Gastrointestinal bleeding has occurred in some patients. Rarely, acute pancreatitis has been reported. Metabolic Reversible hyperuricemia and acute gout have been reported. Acute symptomatic hypoglycemia with convulsions occurred in two uremic patients who received doses above those recommended. Hyperglycemia has been reported. Rarely, jaundice and abnormal liver function tests have been reported in seriously ill patients receiving multiple drug therapy, including ethacrynic acid.

Lithium generally should not be given with diuretics because they reduce its renal clearance and add a high risk of lithium toxicity. Read circulars for lithium preparations before use of such concomitant therapy. Ethacrynic acid may increase the ototoxic potential of other drugs such as aminoglycoside and some cephalosporin antibiotics. Their concurrent use should be avoided. A number of drugs, including ethacrynic acid, have been shown to displace warfarin from plasma protein, a reduction in the usual anticoagulant dosage may be required in patients receiving both drugs. In some patients, the administration of a non-steroidal anti-inflammatory agent can reduce the diuretic, natriuretic, and antihypertensive effects of loop, potassium-sparing and thiazide diuretics.

Storage Store in a tightly closed container at 25°C (77°F), excursions permitted to 15° to 30°C (59° to 86°F).