Spironolactone 100 MG Oral Tablet

Details

Generic Name: SPIRONOLACTONE

Brand Name: Aldactone

Substance Name(s):
SPIRONOLACTONE

WARNINGS

Potassium supplementation Potassium supplementation, either in the form of medication or as a diet rich in potassium, should not ordinarily be given in association with ALDACTONE therapy. Excessive potassium intake may cause hyperkalemia in patients receiving ALDACTONE (see Precautions: General ). Concomitant administration of ALDACTONE with the following drugs or potassium sources may lead to severe hyperkalemia: other potassium-sparing diuretics ACE inhibitors angiotensin II antagonists aldosterone blockers non-steroidal anti-inflammatory drugs (NSAIDs), e.g., indomethacin heparin and low molecular weight heparin other drugs or conditions known to cause hyperkalemia potassium supplements diet rich in potassium salt substitutes containing potassium ALDACTONE should not be administered concurrently with other potassium-sparing diuretics. ALDACTONE, when used with ACE inhibitors or indomethacin, even in the presence of a diuretic, has been associated with severe hyperkalemia. Extreme caution should be exercised when ALDACTONE is given concomitantly with these drugs. Hyperkalemia in patients with severe heart failure Hyperkalemia may be fatal. It is critical to monitor and manage serum potassium in patients with severe heart failure receiving ALDACTONE. Avoid using other potassium-sparing diuretics. Avoid using oral potassium supplements in patients with serum potassium > 3.5 mEq/L. RALES excluded patients with a serum creatinine > 2.5 mg/dL or a recent increase in serum creatinine > 25%. The recommended monitoring for potassium and creatinine is one week after initiation or increase in dose of ALDACTONE, monthly for the first 3 months, then quarterly for a year, and then every 6 months. Discontinue or interrupt treatment for serum potassium > 5 mEq/L or for serum creatinine > 4 mg/dL. (See Clinical Studies: Severe heart failure, and Dosage and Administration: Severe heart failure .) ALDACTONE should be used with caution in patients with impaired hepatic function because minor alterations of fluid and electrolyte balance may precipitate hepatic coma. Lithium generally should not be given with diuretics (see Precautions: Drug interactions ).

DRUG INTERACTIONS

Drug interactions ACE inhibitors Concomitant administration of ACE inhibitors with potassium-sparing diuretics has been associated with severe hyperkalemia. Angiotensin II antagonists, aldosterone blockers, heparin, low molecular weight heparin, and other drugs known to cause hyperkalemia Concomitant administration may lead to severe hyperkalemia. Alcohol, barbiturates, or narcotics Potentiation of orthostatic hypotension may occur. Corticosteroids, ACTH Intensified electrolyte depletion, particularly hypokalemia, may occur. Pressor amines (e.g., norepinephrine) ALDACTONE reduces the vascular responsiveness to norepinephrine. Therefore, caution should be exercised in the management of patients subjected to regional or general anesthesia while they are being treated with ALDACTONE. Skeletal muscle relaxants, nondepolarizing (e.g., tubocurarine) Possible increased responsiveness to the muscle relaxant may result. Lithium Lithium generally should not be given with diuretics. Diuretic agents reduce the renal clearance of lithium and add a high risk of lithium toxicity. Nonsteroidal anti-inflammatory drugs (NSAIDs) In some patients, the administration of an NSAID can reduce the diuretic, natriuretic, and antihypertensive effect of loop, potassium-sparing, and thiazide diuretics. Combination of NSAIDs, e.g., indomethacin, with potassium-sparing diuretics has been associated with severe hyperkalemia. Therefore, when ALDACTONE and NSAIDs are used concomitantly, the patient should be observed closely to determine if the desired effect of the diuretic is obtained. Digoxin ALDACTONE has been shown to increase the half-life of digoxin. This may result in increased serum digoxin levels and subsequent digitalis toxicity. It may be necessary to reduce the maintenance and digitalization doses when ALDACTONE is administered, and the patient should be carefully monitored to avoid over- or under-digitalization. Cholestyramine Hyperkalemic metabolic acidosis has been reported in patients given ALDACTONE concurrently with cholestyramine.

OVERDOSAGE

The oral LD50 of ALDACTONE is greater than 1000 mg/kg in mice, rats, and rabbits. Acute overdosage of ALDACTONE may be manifested by drowsiness, mental confusion, maculopapular or erythematous rash, nausea, vomiting, dizziness, or diarrhea. Rarely, instances of hyponatremia, hyperkalemia, or hepatic coma may occur in patients with severe liver disease, but these are unlikely due to acute overdosage. Hyperkalemia may occur, especially in patients with impaired renal function. Treatment Induce vomiting or evacuate the stomach by lavage. There is no specific antidote. Treatment is supportive to maintain hydration, electrolyte balance, and vital functions. Patients who have renal impairment may develop spironolactone-induced hyperkalemia. In such cases, ALDACTONE should be discontinued immediately. With severe hyperkalemia, the clinical situation dictates the procedures to be employed. These may include the intravenous administration of calcium chloride solution, sodium bicarbonate solution and/or the oral or parenteral administration of glucose with a rapid-acting insulin preparation. These are temporary measures to be repeated as required. Cationic exchange resins such as sodium polystyrene sulfonate may be orally or rectally administered. Persistent hyperkalemia may require dialysis.

DESCRIPTION

ALDACTONE oral tablets contain 25 mg, 50 mg, or 100 mg of the aldosterone antagonist spironolactone, 17-hydroxy-7α-mercapto-3-oxo-17α-pregn-4-ene-21-carboxylic acid γ-lactone acetate, which has the following structural formula: Spironolactone is practically insoluble in water, soluble in alcohol, and freely soluble in benzene and in chloroform. Inactive ingredients include calcium sulfate, corn starch, flavor, hypromellose, iron oxide, magnesium stearate, polyethylene glycol, povidone, and titanium dioxide. Chemical Structure

CLINICAL STUDIES

Severe heart failure The Randomized Aldactone Evaluation Study (RALES) was a multinational, double-blind study in patients with an ejection fraction of ≤ 35%, a history of New York Heart Association (NYHA) class IV heart failure within 6 months, and class III – IV heart failure at the time of randomization. All patients were required to be taking a loop diuretic and, if tolerated, an ACE inhibitor. Patients with a baseline serum creatinine of >2.5 mg/dL or a recent increase of 25% or with a baseline serum potassium of >5.0 mEq/L were excluded. Patients were randomized 1:1 to spironolactone 25 mg orally once daily or matching placebo. Follow-up visits and laboratory measurements (including serum potassium and creatinine) were performed every four weeks for the first 12 weeks, then every 3 months for the first year, and then every 6 months thereafter. Dosing could be withheld for serious hyperkalemia or if the serum creatinine increased to >4.0 mg/dL. Patients who were intolerant of the initial dosage regimen had their dose decreased to one tablet every other day at one to four weeks. Patients who were tolerant of one tablet daily at 8 weeks may have had their dose increased to two tablets daily at the discretion of the investigator. RALES enrolled 1663 patients (3% U.S.) at 195 centers in 15 countries between March 24, 1995 and December 31, 1996. The study population was primarily white (87%, with 7% black, 2% Asian, and 4% other), male (73%), and elderly (median age 67). The median ejection fraction was 0.26. Seventy percent were NYHA class III and 29% class IV. The presumed etiology of heart failure was ischemic in 55%, and non-ischemic in 45%. There was a history of myocardial infarction in 28%, of hypertension in 24%, and of diabetes in 22%. The median baseline serum creatinine was 1.2 mg/dL and the median baseline creatinine clearance was 57 mL/min. The mean daily dose at study end for the patients randomized to spironolactone was 26 mg. Concomitant medications included a loop diuretic in 100% of patients and an ACE inhibitor in 97%. Other medications used at any time during the study included digoxin (78%), anticoagulants (58%), aspirin (43%), and beta-blockers (15%). The primary endpoint for RALES was time to all-cause mortality. RALES was terminated early, after a mean follow-up of 24 months, because of significant mortality benefit detected on a planned interim analysis. The survival curves by treatment group are shown in Figure 1. Figure 1. Survival by Treatment Group in RALES Spironolactone reduced the risk of death by 30% compared to placebo (p<0.001; 95% confidence interval 18% to 40%). Spironolactone reduced the risk of cardiac death, primarily sudden death, and death from progressive heart failure by 31% compared to placebo (p <0.001; 95% confidence interval 18% to 42%). Spironolactone also reduced the risk of hospitalization for cardiac causes (defined as worsening heart failure, angina, ventricular arrhythmias, or myocardial infarction) by 30% (p <0.001 95% confidence interval 18% to 41%). Changes in NYHA class were more favorable with spironolactone: In the spironolactone group, NYHA class at the end of the study improved in 41% of patients and worsened in 38% compared to improved in 33% and worsened in 48% in the placebo group (p <0.001). Mortality hazard ratios for some subgroups are shown in Figure 2. The favorable effect of spironolactone on mortality appeared similar for both genders and all age groups except patients younger than 55; there were too few non-whites in RALES to draw any conclusions about differential effects by race. Spironolactone's benefit appeared greater in patients with low baseline serum potassium levels and less in patients with ejection fractions <0.2. These subgroup analyses must be interpreted cautiously. Figure 2. Hazard Ratios of All-Cause Mortality by Subgroup in RALES Figure 2: The size of each box is proportional to the sample size as well as the event rate. LVEF denotes left ventricular ejection fraction, Ser Creatinine denotes serum creatinine, Cr Clearance denotes creatinine clearance, and ACEI denotes angiotensin-converting enzyme inhibitor. Figure Figure

HOW SUPPLIED

ALDACTONE 25 mg tablets are round, light yellow, film-coated, with SEARLE and 1001 debossed on one side and ALDACTONE and 25 on the other side, supplied as: NDC Number Size 0025-1001-31 bottle of 100 ALDACTONE 50 mg tablets are oval, light orange, scored, film-coated, with SEARLE and 1041 debossed on the scored side and ALDACTONE and 50 on the other side, supplied as: NDC Number Size 0025-1041-31 bottle of 100 ALDACTONE 100 mg tablets are round, peach-colored, scored, film-coated, with SEARLE and 1031 debossed on the scored side and ALDACTONE and 100 on the other side, supplied as: NDC Number Size 0025-1031-31 bottle of 100 Store below 77°F (25°C).

MECHANISM OF ACTION

Mechanism of action ALDACTONE (spironolactone) is a specific pharmacologic antagonist of aldosterone, acting primarily through competitive binding of receptors at the aldosterone-dependent sodium-potassium exchange site in the distal convoluted renal tubule. ALDACTONE causes increased amounts of sodium and water to be excreted, while potassium is retained. ALDACTONE acts both as a diuretic and as an antihypertensive drug by this mechanism. It may be given alone or with other diuretic agents that act more proximally in the renal tubule.

INDICATIONS AND USAGE

ALDACTONE (spironolactone) is indicated in the management of: Primary hyperaldosteronism for: Establishing the diagnosis of primary hyperaldosteronism by therapeutic trial. Short-term preoperative treatment of patients with primary hyperaldosteronism. Long-term maintenance therapy for patients with discrete aldosterone-producing adrenal adenomas who are judged to be poor operative risks or who decline surgery. Long-term maintenance therapy for patients with bilateral micro or macronodular adrenal hyperplasia (idiopathic hyperaldosteronism). Edematous conditions for patients with: Congestive heart failure For the management of edema and sodium retention when the patient is only partially responsive to, or is intolerant of, other therapeutic measures. ALDACTONE is also indicated for patients with congestive heart failure taking digitalis when other therapies are considered inappropriate. Cirrhosis of the liver accompanied by edema and/or ascites Aldosterone levels may be exceptionally high in this condition. ALDACTONE is indicated for maintenance therapy together with bed rest and the restriction of fluid and sodium. Nephrotic syndrome For nephrotic patients when treatment of the underlying disease, restriction of fluid and sodium intake, and the use of other diuretics do not provide an adequate response. Essential hypertension ALDACTONE is indicated for the treatment of hypertension, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. These benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes. Control of high blood pressure should be part of comprehensive cardiovascular risk management, including, as appropriate, lipid control, diabetes management, antithrombotic therapy, smoking cessation, exercise, and limited sodium intake. Many patients will require more than one drug to achieve blood pressure goals. For specific advice on goals and management, see published guidelines, such as those of the National High Blood Pressure Education Program’s Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC). Numerous antihypertensive drugs, from a variety of pharmacologic classes and with different mechanisms of action, have been shown in randomized controlled trials to reduce cardiovascular morbidity and mortality, and it can be concluded that it is blood pressure reduction, and not some other pharmacologic property of the drugs, that is largely responsible for those benefits. The largest and most consistent cardiovascular outcome benefit has been a reduction in the risk of stroke, but reductions in myocardial infarction and cardiovascular mortality also have been seen regularly. Elevated systolic or diastolic pressure causes increased cardiovascular risk, and the absolute risk increase per mmHg is greater at higher blood pressures, so that even modest reductions of severe hypertension can provide substantial benefit. Relative risk reduction from blood pressure reduction is similar across populations with varying absolute risk, so the absolute benefit is greater in patients who are at higher risk independent of their hypertension (for example, patients with diabetes or hyperlipidemia), and such patients would be expected to benefit from more aggressive treatment to a lower blood pressure goal. Some antihypertensive drugs have smaller blood pressure effects (as monotherapy) in black patients, and many antihypertensive drugs have additional approved indications and effects (e.g., on angina, heart failure, or diabetic kidney disease). These considerations may guide selection of therapy. Usually in combination with other drugs, ALDACTONE is indicated for patients who cannot be treated adequately with other agents or for whom other agents are considered inappropriate. Hypokalemia For the treatment of patients with hypokalemia when other measures are considered inappropriate or inadequate. ALDACTONE is also indicated for the prophylaxis of hypokalemia in patients taking digitalis when other measures are considered inadequate or inappropriate. Severe heart failure (NYHA class III – IV) To increase survival, and to reduce the need for hospitalization for heart failure when used in addition to standard therapy. Usage in Pregnancy The routine use of diuretics in an otherwise healthy woman is inappropriate and exposes mother and fetus to unnecessary hazard. Diuretics do not prevent development of toxemia of pregnancy, and there is no satisfactory evidence that they are useful in the treatment of developing toxemia. Edema during pregnancy may arise from pathologic causes or from the physiologic and mechanical consequences of pregnancy. ALDACTONE is indicated in pregnancy when edema is due to pathologic causes just as it is in the absence of pregnancy (however, see Precautions: Pregnancy ). Dependent edema in pregnancy, resulting from restriction of venous return by the expanded uterus, is properly treated through elevation of the lower extremities and use of support hose; use of diuretics to lower intravascular volume in this case is unsupported and unnecessary. There is hypervolemia during normal pregnancy which is not harmful to either the fetus or the mother (in the absence of cardiovascular disease), but which is associated with edema, including generalized edema, in the majority of pregnant women. If this edema produces discomfort, increased recumbency will often provide relief. In rare instances, this edema may cause extreme discomfort that is not relieved by rest. In these cases, a short course of diuretics may provide relief and may be appropriate.

PEDIATRIC USE

Pediatric use Safety and effectiveness in pediatric patients have not been established.

PREGNANCY

Usage in Pregnancy The routine use of diuretics in an otherwise healthy woman is inappropriate and exposes mother and fetus to unnecessary hazard. Diuretics do not prevent development of toxemia of pregnancy, and there is no satisfactory evidence that they are useful in the treatment of developing toxemia. Edema during pregnancy may arise from pathologic causes or from the physiologic and mechanical consequences of pregnancy. ALDACTONE is indicated in pregnancy when edema is due to pathologic causes just as it is in the absence of pregnancy (however, see Precautions: Pregnancy ). Dependent edema in pregnancy, resulting from restriction of venous return by the expanded uterus, is properly treated through elevation of the lower extremities and use of support hose; use of diuretics to lower intravascular volume in this case is unsupported and unnecessary. There is hypervolemia during normal pregnancy which is not harmful to either the fetus or the mother (in the absence of cardiovascular disease), but which is associated with edema, including generalized edema, in the majority of pregnant women. If this edema produces discomfort, increased recumbency will often provide relief. In rare instances, this edema may cause extreme discomfort that is not relieved by rest. In these cases, a short course of diuretics may provide relief and may be appropriate.

NUSRING MOTHERS

Nursing mothers Canrenone, a major (and active) metabolite of ALDACTONE, appears in human breast milk. Because ALDACTONE has been found to be tumorigenic in rats, a decision should be made whether to discontinue the drug, taking into account the importance of the drug to the mother. If use of the drug is deemed essential, an alternative method of infant feeding should be instituted.

BOXED WARNING

WARNING ALDACTONE has been shown to be a tumorigen in chronic toxicity studies in rats (see Precautions ). ALDACTONE should be used only in those conditions described under Indications and Usage. Unnecessary use of this drug should be avoided.

INFORMATION FOR PATIENTS

Information for patients Patients who receive ALDACTONE should be advised to avoid potassium supplements and foods containing high levels of potassium, including salt substitutes.

DOSAGE AND ADMINISTRATION

Primary hyperaldosteronism ALDACTONE may be employed as an initial diagnostic measure to provide presumptive evidence of primary hyperaldosteronism while patients are on normal diets. Long test ALDACTONE is administered at a daily dosage of 400 mg for three to four weeks. Correction of hypokalemia and of hypertension provides presumptive evidence for the diagnosis of primary hyperaldosteronism. Short test ALDACTONE is administered at a daily dosage of 400 mg for four days. If serum potassium increases during ALDACTONE administration but drops when ALDACTONE is discontinued, a presumptive diagnosis of primary hyperaldosteronism should be considered. After the diagnosis of hyperaldosteronism has been established by more definitive testing procedures, ALDACTONE may be administered in doses of 100 to 400 mg daily in preparation for surgery. For patients who are considered unsuitable for surgery, ALDACTONE may be employed for long-term maintenance therapy at the lowest effective dosage determined for the individual patient. Edema in adults (congestive heart failure, hepatic cirrhosis, or nephrotic syndrome) An initial daily dosage of 100 mg of ALDACTONE administered in either single or divided doses is recommended, but may range from 25 to 200 mg daily. When given as the sole agent for diuresis, ALDACTONE should be continued for at least five days at the initial dosage level, after which it may be adjusted to the optimal therapeutic or maintenance level administered in either single or divided daily doses. If, after five days, an adequate diuretic response to ALDACTONE has not occurred, a second diuretic that acts more proximally in the renal tubule may be added to the regimen. Because of the additive effect of ALDACTONE when administered concurrently with such diuretics, an enhanced diuresis usually begins on the first day of combined treatment; combined therapy is indicated when more rapid diuresis is desired. The dosage of ALDACTONE should remain unchanged when other diuretic therapy is added. Essential hypertension For adults, an initial daily dosage of 50 to 100 mg of ALDACTONE administered in either single or divided doses is recommended. ALDACTONE may also be given with diuretics that act more proximally in the renal tubule or with other antihypertensive agents. Treatment with ALDACTONE should be continued for at least two weeks since the maximum response may not occur before this time. Subsequently, dosage should be adjusted according to the response of the patient. Hypokalemia ALDACTONE in a dosage ranging from 25 mg to 100 mg daily is useful in treating a diuretic-induced hypokalemia, when oral potassium supplements or other potassium-sparing regimens are considered inappropriate. Severe heart failure in conjunction with standard therapy (NYHA class III – IV) Treatment should be initiated with ALDACTONE 25 mg once daily if the patient’s serum potassium is ≤5.0 mEq/L and the patient’s serum creatinine is ≤ 2.5 mg/dL. Patients who tolerate 25 mg once daily may have their dosage increased to 50 mg once daily as clinically indicated. Patients who do not tolerate 25 mg once daily may have their dosage reduced to 25 mg every other day. See Warnings: Hyperkalemia in patients with severe heart failure for advice on monitoring serum potassium and serum creatinine.