Spironolactone 25 MG Oral Tablet
Generic Name: SPIRONOLACTONE
Brand Name: Spironolactone
- 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 spironolactone therapy. Excessive potassium intake may cause hyperkalemia in patients receiving spironolactone (see Precautions: General). Spironolactone should not be administered concurrently with other potassium-sparing diuretics. Spironolactone, 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 spironolactone 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 spironolactone. Avoid using other potassium-sparing diuretics. Avoid using oral potassium supplements in patients with serum potassium > 3.5 mEq/L. The Randomized Spironolactone Evaluation Study 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 spironolactone, 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.) Spironolactone 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).
OVERDOSAGE
The oral LD50 of spironolactone is greater than 1,000 mg/kg in mice, rats, and rabbits. Acute overdosage of spironolactone 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, spironolactone should be discontinued immediately. With severe hyperkalemia, the clinical situation dictates the procedures to be employed. These 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
Spironolactone 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, croscarmellose sodium, flavor, hypromellose, iron oxide magnesium stearate, microcrystalline cellulose, polydextrose, polyethylene glycol, polyvinyl alcohol, povidone, talc, titanium dioxide, and triacetin. The 50 mg tablet also contains D&C yellow # 10 and FD&C yellow # 6. 9943249f-figure-01
CLINICAL STUDIES
Severe heart failure: A Randomized Spironolactone Evaluation Study was conducted. The Randomized Spironolactone Evaluation Study 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. The Randomized Spironolactone Evaluation Study enrolled 1,663 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 the Randomized Spironolactone Evaluation Study was time to all-cause mortality. The study 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 the Randomized Spironolactone Evaluation Study 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 enrolled in the Randomized Spironolactone Evaluation Study 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 the Randomized Spironolactone Evaluation Study Figure 2: The size of each box is proportional to the sample size as well as the event rate. ACEI denotes angiotensin-converting enzyme inhibitor, LVEF denotes left ventricular ejection fraction, Cr Clearance denotes creatinine clearance and Ser Creatinine denotes serum creatinine. 9943249f-figure-02 9943249f-figure-03
HOW SUPPLIED
Spironolactone Tablets, USP 25 mg are white, film-coated, round tablets, debossed “AN” above “511” on one side and plain on other side. Supplied in: Boxes of 10×10 UD 100 NDC 63739-544-10 Spironolactone Tablets, USP 50 mg are yellow, film-coated, round tablets, debossed “AN” bisect “514” on one side and plain on other side. Supplied in: Boxes of 10×10 UD 100 NDC 63739-545-10 Store at 20° to 25°C (68° to 77°F) (see USP Controlled Room Temperature). Dispense in a tight, light-resistant container. Manufactured by: Amneal Pharmaceuticals Hauppauge, NY 11788 Distributed by: McKesson Packaging Services a business unit of McKesson Corporation 7101 Weddington Rd., Concord, NC 28027 Issued March 2011 IS-4010694
INDICATIONS AND USAGE
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. Spironolactone 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: Spironolactone levels may be exceptionally high in this condition. Spironolactone is indicated for maintenance therapy together with bed rest and the restriction of fluid and sodium. The 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 Usually in combination with other drugs, spironolactone 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. Spironolactone 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. Spironolactone 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 which is not relieved by rest. In these cases, a short course of diuretics may provide relief and may be appropriate.
BOXED WARNING
WARNING Spironolactone Tablets have been shown to be a tumorigen in chronic toxicity studies in rats (see Precautions). Spironolactone Tablets should be used only in those conditions described under Indications and Usage. Unnecessary use of this drug should be avoided.
DOSAGE AND ADMINISTRATION
Primary hyperaldosteronism. Spironolactone may be employed as an initial diagnostic measure to provide presumptive evidence of primary hyperaldosteronism while patients are on normal diets. Long test: Spironolactone 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: Spironolactone is administered at a daily dosage of 400 mg for four days. If serum potassium increases during spironolactone administration but drops when spironolactone is discontinued, a presumptive diagnosis of primary hyperaldosteronism should be considered. After the diagnosis of hyperaldosteronism has been established by more definitive testing procedures, spironolactone may be administered in doses of 100 to 400 mg daily in preparation for surgery. For patients who are considered unsuitable for surgery, spironolactone 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 spironolactone 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, spionolactone 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 spironolactone has not occurred, a second diuretic which acts more proximally in the renal tubule may be added to the regimen. Because of the additive effect of spironolactone 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 spironolactone should remain unchanged when other diuretic therapy is added. Essential hypertension. For adults, an initial daily dosage of 50 to 100 mg of spironolactone administered in either single or divided doses is recommended. Spironolactone may also be given with diuretics which act more proximally in the renal tubule or with other antihypertensive agents. Treatment with spironolactone 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. Spironolactone 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 (NYHA class III – IV). Treatment should be initiated with spironolactone 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 dose 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.