ETHACRYNIC SODIUM- ethacrynate sodium powder, for solution
ETHACRYNIC ACID- ethacrynic acid tablet
Oceanside Pharmaceuticals
Ethacrynic acid is a potent diuretic which, if given in excessive amounts, may lead to profound diuresis with water and electrolyte depletion. Therefore, careful medical supervision is required, and dose and dose schedule must be adjusted to the individual patient's needs (see DOSAGE AND ADMINISTRATION).
DESCRIPTION
Ethacrynic acid is an unsaturated ketone derivative of an aryloxyacetic acid. It is designated chemically as [2,3-dichloro-4-(2-methylene-1-oxobutyl)phenoxy]acetic acid, and has a molecular weight of 303.14. Ethacrynic acid is a white, or practically white, crystalline powder, very slightly soluble in water, but soluble in most organic solvents such as alcohols, chloroform, and benzene. Its empirical formula is C13 H12 Cl2 O4 and its structural formula is:
Ethacrynate sodium, the sodium salt of ethacrynic acid, is soluble in water at 25�C to the extent of about 7 percent.
Solutions of the sodium salt are relatively stable at about pH 7 at room temperature for short periods, but as the pH or temperature increases the solutions are less stable. The molecular weight of ethacrynate sodium is 325.12. Its empirical formula is C13 H11 Cl2 NaO4 and its structural formula is:
Ethacrynic acid is supplied as 25 mg tablets for oral use. The tablets contain the following inactive ingredients: colloidal silicon dioxide, lactose, magnesium stearate, starch and talc.
Intravenous Ethacrynate sodium is a sterile freeze-dried powder and is supplied in a vial containing:
Ethacrynate sodium equivalent to ethacrynic acid . . . . . . . . . 50.0 mg
Inactive ingredient:
Mannitol. . . . . . . . . . . . . . . . . 62.5 mg
CLINICAL PHARMACOLOGY
Pharmacokinetics and Metabolism
Ethacrynic acid acts on the ascending limb of the loop of Henle and on the proximal and distal tubules. Urinary output is usually dose dependent and related to the magnitude of fluid accumulation. Water and electrolyte excretion may be increased several times over that observed with thiazide diuretics, since ethacrynic acid inhibits reabsorption of a much greater proportion of filtered sodium than most other diuretic agents. Therefore, ethacrynic acid is effective in many patients who have significant degrees of renal insufficiency (see WARNINGS concerning deafness). Ethacrynic acid has little or no effect on glomerular filtration or on renal blood flow, except following pronounced reductions in plasma volume when associated with rapid diuresis.