Aldactone (spironolactone) is a prescription medication belonging to the class of potassium-sparing diuretics. It functions as a competitive antagonist of aldosterone, primarily acting on the distal renal tubules to promote sodium and water excretion while conserving potassium. This mechanism makes it a cornerstone therapy for managing conditions like heart failure, hypertension, and edema associated with hepatic cirrhosis or nephrotic syndrome. Its antiandrogenic properties also lend utility in treating hormonal acne and hirsutism in women. Clinicians value Aldactone for its dual action in fluid management and potassium preservation, reducing the need for supplemental potassium in many therapeutic regimens.

Features

• Active ingredient: Spironolactone
• Drug class: Potassium-sparing diuretic
• Available formulations: 25 mg, 50 mg, and 100 mg tablets
• Mechanism: Competitive aldosterone receptor antagonist
• Bioavailability: >90% following oral administration
• Half-life: 1.3–1.4 hours (parent drug); 13–24 hours (active metabolites)
• Metabolism: Hepatic, via CYP3A4 to active metabolites
• Excretion: Primarily renal (40–57%) and biliary (35–40%)

Benefits

• Effectively reduces edema and fluid retention without causing hypokalemia
• Provides cardioprotective effects in heart failure by counteracting neurohormonal activation
• Offers antihypertensive action with favorable metabolic profile
• Demonstrates antiandrogenic activity for dermatological and endocrine applications
• Reduces hospitalizations and mortality in appropriate heart failure populations
• May improve renal outcomes in selected proteinuric kidney diseases

Common use

Aldactone is primarily indicated for the management of edema in congestive heart failure, cirrhosis of the liver accompanied by edema and/or ascites, nephrotic syndrome, and essential hypertension. It is also used diagnostically and therapeutically in primary hyperaldosteronism. Off-label applications include treatment of hirsutism in women, acne vulgaris, female pattern hair loss, and as adjunctive therapy in hypokalemia prevention. In heart failure with reduced ejection fraction, Aldactone is standard care for patients who remain symptomatic despite ACE inhibitor and beta-blocker therapy.

Dosage and direction

Dosage must be individualized based on the condition being treated and patient response. For edema in adults: initial dose is 100 mg daily in single or divided doses, may be titrated to effect. For hypertension: initial dose 50–100 mg daily in single or divided doses. For heart failure: starting dose 25 mg once daily, with titration to 50 mg once daily if tolerated. For primary hyperaldosteronism: 100–400 mg daily in preparation for surgery or for long-term maintenance. Tablets should be taken with meals to enhance absorption. Regular monitoring of serum electrolytes, particularly potassium, is essential during therapy.

Precautions

Patients should be monitored for hyperkalemia, especially those with renal impairment, diabetes, or those taking other potassium-raising medications. Regular assessment of renal function is recommended. Use with caution in patients with hepatic impairment due to potential for electrolyte imbalance and hepatic encephalopathy. May cause gynecomastia in males and menstrual irregularities in females. Caution advised in elderly patients who may be more susceptible to electrolyte disturbances. Photosensitivity reactions may occur; sun protection measures are recommended. Patients should avoid potassium supplements and high-potassium diets unless specifically directed by their physician.

Contraindications

Aldactone is contraindicated in patients with anuria, acute renal insufficiency, significant impairment of renal function, or hyperkalemia. Additional contraindications include Addison’s disease and concomitant use with eplerenone. Hypersensitivity to spironolactone or any component of the formulation prohibits use. Should not be used during pregnancy due to potential antiandrogenic effects on the developing male fetus. Avoid use in patients with severe hepatic impairment where electrolyte imbalance might precipitate hepatic encephalopathy.

Possible side effect

Common adverse reactions include hyperkalemia (especially with renal impairment), gynecomastia, breast pain, menstrual irregularities, diarrhea, nausea, vomiting, headache, and drowsiness. Less frequently reported effects include erectile dysfunction, decreased libido, rash, leukopenia, agranulocytosis, and hepatic dysfunction. Electrolyte disturbances including hyponatremia and hypomagnesemia may occur. Rare cases of Stevens-Johnson syndrome, toxic epidermal necrolysis, and anaphylactic reactions have been reported. Most side effects are dose-dependent and may resolve with dosage reduction or discontinuation.

Drug interaction

Significant interactions occur with ACE inhibitors, ARBs, NSAIDs, potassium supplements, and other potassium-sparing diuretics, increasing hyperkalemia risk. Concurrent use with digoxin may increase digoxin levels. Spironolactone may enhance the effects of other antihypertensive agents. CYP3A4 inhibitors (ketoconazole, itraconazole, ritonavir) may increase spironolactone concentrations. May reduce the effectiveness of oral anticoagulants. Concomitant use with lithium may increase lithium toxicity risk. NSAIDs may reduce the diuretic and antihypertensive effects of spironolactone.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next scheduled dose. In that case, the missed dose should be skipped and the regular dosing schedule resumed. Patients should not double the dose to make up for a missed administration. Consistent daily dosing is important for maintaining therapeutic effect, particularly in hypertension and heart failure management. Patients should be educated about the importance of adherence to prescribed dosing regimens.

Overdose

Symptoms of overdose primarily manifest as electrolyte disturbances, particularly hyperkalemia, which may present as muscle weakness, paralysis, cardiac conduction abnormalities, and potentially fatal arrhythmias. Hyponatremia may cause confusion, seizures, and coma. Gastric lavage or emesis may be considered if ingestion was recent. Treatment is supportive and includes discontinuation of the drug, potassium restriction, and management of electrolyte abnormalities. Severe hyperkalemia may require calcium gluconate, insulin with glucose, sodium bicarbonate, or dialysis. There is no specific antidote for spironolactone overdose.

Storage

Store at controlled room temperature (20–25°C or 68–77°F) in the original container with the lid tightly closed. Protect from light and moisture. Keep out of reach of children and pets. Do not store in bathroom cabinets where humidity may affect stability. Properly discard any medication that is outdated or no longer needed. Do not flush medications down the toilet or pour into drains unless specifically instructed to do so.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Aldactone is a prescription medication that should only be used under the supervision of a qualified healthcare professional. Individual patient responses may vary, and therapeutic decisions should be based on comprehensive clinical evaluation. Always consult with a healthcare provider for diagnosis and treatment recommendations. Full prescribing information should be reviewed before initiating therapy.

Reviews

Clinical studies consistently demonstrate Aldactone’s efficacy in heart failure management, with the RALES trial showing 30% reduction in mortality among severe heart failure patients. In dermatological applications, multiple studies report significant improvement in hormonal acne and hirsutism, with 60-80% of patients showing clinical improvement. Hypertension studies indicate effective blood pressure reduction with preservation of potassium balance. Most expert reviews highlight its unique mechanism of action and valuable role in comprehensive therapeutic regimens, though they emphasize the need for careful monitoring due to hyperkalemia risk.