Indication

Spironolactone is indicated in the management of oedema and ascites in cirrhosis of the liver, malignant ascites, nephrotic syndrome, congestive heart failure and primary hyperaldosteronism.

Dosage & 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.

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, Spironolactone 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.

Precautions

All patients receiving diuretic therapy should be observed for evidence of fluid or electrolyte imbalance, e.g., hypomagnesemia, hyponatremia, hypochloremic alkalosis, and hyperkalemia. Serum and urine electrolyte determinations are particularly important when the patient is vomiting excessively or receiving parenteral fluids. Warning signs or symptoms of fluid and electrolyte imbalance, irrespective of cause, include dryness of the mouth, thirst, weakness, lethargy, drowsiness, restlessness, muscle pains or cramps, muscular fatigue, hypotension, oliguria, tachycardia, and gastrointestinal disturbances such as nausea and vomiting. Hyperkalemia may occur in patients with impaired renal function or excessive potassium intake and can cause cardiac irregularities, which may be fatal. Consequently, no potassium supplement should ordinarily be given with Spironolactone. Use in Pregnancy and Lactation: The effects of Spironolactone during pregnancy have not been adequately studied. Spironolactone appears in breast milk and could affect a nursing infant.