ETHACRYNATE SODIUM
ETHACRYNATE SODIUM
Indications and usage INDICATIONS AND USAGE Ethacrynate sodium is indicated for treatment of edema when an agent with greater diuretic potential than those commonly employed is required.
Treatment of the edema associated with congestive heart failure, cirrhosis of the liver and renal disease, including the nephrotic syndrome.
Structured Monograph
Clinical summary
Indications and usage INDICATIONS AND USAGE Ethacrynate sodium is indicated for treatment of edema when an agent with greater diuretic potential than those commonly employed is required. Treatment of the edema associated with congestive heart failure, cirrhosis of the liver and renal disease, including the nephrotic syndrome. Short-term management of ascites due to malignancy, idiopathic edema, and lymphedema. Short-term management of hospitalized pediatric patients, other than infants, with congenital heart disease or the nephrotic syndrome. 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 and administration DOSAGE AND ADMINISTRATION 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 Tablets USP are available 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. Dosage adjustments are usually in 25 to 50 mg increments to avoid derangement of water and electrolyte excretion. The patient should be weighed under standard conditions before and during the institution of diuretic therapy with this compound: The following schedule may be helpful in determining the smallest effective dose. Day 1 - 50 mg once daily after a meal Day 2 - 50 mg twice daily after meals, if necessary Day 3 - 100 mg in the morning and 50 to 100 mg following the afternoon or evening meal, depending upon response to the morning dose A few patients may require initial and maintenance doses as high as 200 mg twice daily. These higher doses, which should be achieved gradually, are most often required in patients with severe, refractory edema. In Pediatric Patients (excluding infants, see CONTRAINDICATIONS ): The initial dose should be 25 mg. Careful stepwise increments in dosage of 25 mg should be made to achieve effective maintenance. Maintenance Therapy It is usually possible to reduce the dosage and frequency of administration once dry weight has been achieved. Ethacrynic Acid Tablets USP may be given intermittently after an effective diuresis is obtained with the regimen outlined above. Dosage may be on an alternate daily schedule or more prolonged periods of diuretic therapy may be interspersed with rest periods. Such an intermittent dosage schedule allows time for correction of any electrolyte imbalance and may provide a more efficient diuretic response. The chloruretic effect of this agent may give rise to retention of bicarbonate and a metabolic alkalosis. This may be corrected by giving chloride (ammonium chloride or arginine chloride). Ammonium chloride should not be given to cirrhotic patients. Ethacrynic Acid Tablets USP has additive effects when used with other diuretics. For example, a patient who is on maintenance dosage of an oral diuretic may require additional intermittent diuretic therapy, such as an organomercurial, for the maintenance of basal weight. The intermittent use of Ethacrynic Acid Tablets USP orally may eliminate the need for injections of organomercurials. Small doses of Ethacrynic Acid Tablets USP may be added to existing diuretic regimens to maintain basal weight. This drug may potentiate the action of carbonic anhydrase inhibitors, with augmentation of natriuresis and kaliuresis. Therefore, when adding Ethacrynic Acid Tablets USP the initial dose and changes of dose should be in 25 mg increments, to avoid electrolyte depletion. Rarely, patients who failed to respond to ethacrynic acid have responded to older established agents. While many patients do not require supplemental potassium, the use of potassium chloride or potassium-sparing agents, or both, during treatment with Ethacrynic Acid Tablets USP is advisable, especially in cirrhotic or nephrotic patients and in patients receiving digitalis. Salt liberalization usually prevents the development of hyponatremia and hypochloremia. During treatment with Ethacrynic Acid Tablets USP, salt may be liberalized to a greater extent than with other diuretics. Cirrhotic patients, however, usually require at least moderate salt restriction concomitant with diuretic therapy. Intravenous Use Intravenous ethacrynate sodium is for intravenous use when oral intake is impractical or in urgent conditions, such as acute pulmonary edema. Th
Monitoring
- • WARNINGS 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.
Interaction Notes
- • Drug Interactions 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.
- • Ethacrynate sodium may increase the ototoxic potential of other drugs such as aminoglycoside and some cephalosporin antibiotics.
- • Their concurrent use should be avoided.