ALDACTAZIDE- spironolactone and hydrochlorothiazide tablet, film coated
G.D. Searle LLC Division of Pfizer Inc
WARNING
Spironolactone, an ingredient of ALDACTAZIDE, has been shown to be a tumorigen in chronic toxicity studies in rats (see Precautions). ALDACTAZIDE should be used only in those conditions described under Indications and Usage. Unnecessary use of this drug should be avoided.
Fixed-dose combination drugs are not indicated for initial therapy of edema or hypertension. Edema or hypertension requires therapy titrated to the individual patient. If the fixed combination represents the dosage so determined, its use may be more convenient in patient management. The treatment of hypertension and edema is not static but must be reevaluated as conditions in each patient warrant.
DESCRIPTION
ALDACTAZIDE oral tablets contain:
spironolactone . . . . . . . . . . . . . . . . . . . . 25 mg
hydrochlorothiazide . . . . . . . . . . . . . . . . 25 mg
or
spironolactone . . . . . . . . . . . . . . . . . . . . 50 mghydrochlorothiazide . . . . . . . . . . . . . . . . 50 mg
Spironolactone (ALDACTONE�), an aldosterone antagonist, is 17-hydroxy-7?-mercapto-3-oxo-17?-pregn-4-ene-21-carboxylic acid ?-lactone acetate
Hydrochlorothiazide, a diuretic and antihypertensive, is 6-chloro-3,4-dihydro-2H-1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide
ACTIONS / CLINICAL PHARMACOLOGY
Mechanism of action
ALDACTAZIDE is a combination of two diuretic agents with different but complementary mechanisms and sites of action, thereby providing additive diuretic and antihypertensive effects. Additionally, the spironolactone component helps to minimize the potassium loss characteristically induced by the thiazide component.
The diuretic effect of spironolactone is mediated through its action as a specific pharmacologic antagonist of aldosterone, primarily by competitive binding of receptors at the aldosterone-dependent sodium-potassium exchange site in the distal convoluted renal tubule. Hydrochlorothiazide promotes the excretion of sodium and water primarily by inhibiting their reabsorption in the cortical diluting segment of the distal renal tubule.
ALDACTAZIDE is effective in significantly lowering the systolic and diastolic blood pressure in many patients with essential hypertension, even when aldosterone secretion is within normal limits.
Both spironolactone and hydrochlorothiazide reduce exchangeable sodium, plasma volume, body weight, and blood pressure. The diuretic and antihypertensive effects of the individual components are potentiated when spironolactone and hydrochlorothiazide are given concurrently.
INDICATIONS AND USAGE
Spironolactone, an ingredient of ALDACTAZIDE, has been shown to be a tumorigen in chronic toxicity studies in rats (see Precautions section). ALDACTAZIDE should be used only in those conditions described below. Unnecessary use of this drug should be avoided.