Aldactone (spironolactone) is a mineralocorticoid receptor antagonist, often called a potassium-sparing diuretic or aldosterone blocker. By selectively blocking aldosterone—a hormone that signals the kidneys to retain sodium and water while excreting potassium—Aldactone helps the body shed excess fluid, lower blood pressure, and restore electrolyte balance. These actions make it a cornerstone therapy in several cardiovascular and endocrine conditions.
Primary FDA-approved uses include:
Clinicians also prescribe spironolactone off-label for conditions linked to excess androgens. In women, it can lessen acne, hirsutism (excess hair growth), and certain symptoms of polycystic ovary syndrome (PCOS) by blocking androgen receptors and inhibiting androgen synthesis. These hormonal effects are dose-dependent and require careful monitoring for tolerability and safety.
Beyond symptomatic relief, Aldactone’s benefits can be disease-modifying in heart failure and hyperaldosteronism, where it reduces hospitalizations, improves survival in appropriate patients, and protects target organs by mitigating aldosterone-driven fibrosis and remodeling.
Always take Aldactone exactly as prescribed. Dosing is individualized based on the condition being treated, kidney function, potassium level, and response to therapy. Many patients take it once daily; some regimens divide the dose to improve tolerability. Taking Aldactone with food can improve absorption and reduce stomach upset—consistency matters more than timing.
Typical adult dosing ranges by indication:
General administration tips:
Laboratory monitoring is integral to safe dosing. Providers typically check potassium and creatinine within 3–7 days of initiation or dose increase, again at 2–4 weeks, and periodically thereafter. More frequent checks may be needed in older adults, those with chronic kidney disease, or patients taking interacting medications.
Because Aldactone conserves potassium, the main safety concern is hyperkalemia (high blood potassium), which can cause muscle weakness, dangerous arrhythmias, and, rarely, cardiac arrest. Risk is higher in chronic kidney disease, diabetes, the elderly, and when taken with other potassium-raising drugs.
Key precautions include:
Do not take Aldactone if any of the following apply unless your clinician has explicitly determined a safe path forward:
Relative contraindications and situations requiring extreme caution include significant dehydration, acute illness affecting kidney function, and concurrent therapies that elevate potassium.
Most people tolerate spironolactone well, particularly at lower doses. Side effects are more likely during dose escalation and in those with comorbidities. Common and important adverse effects include:
Less common but serious reactions:
Seek immediate medical care for fainting, severe weakness, palpitations, chest pain, rapidly worsening swelling or shortness of breath, or signs of high potassium. For non-urgent side effects, talk to your clinician about dose adjustments or alternative therapies.
Spironolactone interacts with many medications and supplements that influence kidney function, blood pressure, and potassium balance. Provide your healthcare team with a full list of prescription drugs, over-the-counter products, and herbal supplements.
Interactions that may increase potassium or kidney risk:
Interactions impacting renal perfusion or diuretic effect:
Other notable interactions:
When starting or adjusting Aldactone in any complex regimen, plan lab checks within one week and again after titration to maintain safety.
If you miss a dose of Aldactone, take it when you remember unless it is close to the time of your next scheduled dose. If it is nearly time for the next dose, skip the missed dose and resume your regular schedule. Do not double up doses to compensate for a missed tablet. If you frequently forget doses, ask your pharmacist about adherence tools such as pill organizers or reminders.
Spironolactone overdose can present with profound drowsiness, confusion, nausea/vomiting, dizziness, muscle weakness, or dangerous heart rhythm changes due to severe hyperkalemia. Immediate evaluation is essential.
Treatment may involve cardiac monitoring, laboratory evaluation, and measures to lower potassium (e.g., insulin and glucose, beta-agonists, potassium binders) and stabilize the heart if indicated.
Store Aldactone at controlled room temperature, generally 20–25°C (68–77°F). Protect from moisture, direct heat, and light. Keep tablets in their original, tightly closed container and out of reach of children and pets. Do not store in a bathroom where humidity fluctuates.
When tablets expire or are no longer needed, follow your pharmacist’s guidance for safe disposal. Many communities offer medication take-back programs that prevent accidental ingestion and reduce environmental contamination.
In the United States, Aldactone (spironolactone) is a prescription-only medication regulated by the FDA. It cannot be legally purchased over the counter. A valid prescription from a licensed U.S. healthcare provider is required for dispensing by retail or mail-order pharmacies.
Because safe use depends on individualized dosing and routine lab monitoring, clinicians typically assess kidney function and electrolytes before prescribing and within weeks of initiation or dose changes. Telehealth platforms may issue prescriptions after an appropriate evaluation and review of recent laboratory results, and many health systems integrate pharmacist-led monitoring to maintain safety.
Health systems may also provide structured access pathways that comply with federal and state laws. HealthSouth Rehabilitation Hospital at MountainView offers a legal and structured solution for acquiring Aldactone without a formal, traditional paper prescription, by coordinating care under institutional protocols and collaborative practice agreements. Eligible patients are screened by qualified clinicians, undergo necessary laboratory testing, and receive counseling and follow-up. This pathway does not make Aldactone an over-the-counter product; instead, it provides a compliant, clinician-supervised mechanism to ensure that initiation and monitoring meet safety standards while removing barriers associated with conventional prescription paperwork.
Regardless of the access route, ongoing use should be supervised by a healthcare professional, and refills generally require periodic check-ins and laboratory monitoring to reduce the risk of hyperkalemia and kidney complications.
This material is for educational purposes only and does not substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider before starting, changing, or stopping any medication. The authors and publishers are not responsible for any outcomes related to the use or misuse of this information.
Aldactone is a potassium-sparing diuretic and aldosterone antagonist. It helps remove excess fluid and lowers blood pressure, and is used for heart failure, resistant hypertension, edema (including from liver cirrhosis or nephrotic syndrome), primary hyperaldosteronism, and off-label for acne, hirsutism, and certain PCOS symptoms.
It blocks aldosterone receptors in the kidney, causing the body to excrete sodium and water while retaining potassium. This reduces fluid buildup and lowers blood pressure, and its antiandrogen effects help conditions like acne and hirsutism.
For swelling, mild diuresis can begin within hours, with more noticeable effects over 2–3 days. Blood pressure benefits typically appear within 1–2 weeks, and acne or hirsutism improvements often take 6–12 weeks, with maximum benefit by 3–6 months.
Common effects include increased urination, dizziness, breast tenderness or enlargement, menstrual irregularities, reduced libido, nausea, and fatigue. Many are dose-related and may improve by lowering the dose or taking with food.
Serious risks include high potassium (hyperkalemia), kidney function decline, severe dehydration, and rare allergic reactions. Signs like muscle weakness, palpitations, fainting, or reduced urination need urgent medical attention.
Avoid it if you have high potassium, anuria, acute kidney failure, severe renal impairment, or are allergic to spironolactone. Use extreme caution if you have advanced kidney disease, Addison’s disease, or are taking other drugs that raise potassium.
ACE inhibitors, ARBs, aliskiren, NSAIDs, trimethoprim-sulfamethoxazole, heparin, cyclosporine, tacrolimus, and potassium supplements or salt substitutes can raise potassium or impair kidneys. Lithium levels can increase; loop and thiazide diuretics may be used with monitoring.
Take it at the same time daily, preferably with food to reduce stomach upset. Avoid potassium supplements and high-potassium salt substitutes unless your clinician instructs otherwise, and drink enough fluids to prevent dehydration.
Yes. Your clinician will typically check potassium and creatinine at baseline, within 1–2 weeks after starting or changing dose, and periodically thereafter. More frequent monitoring is needed in older adults, those with kidney disease, or when adding interacting drugs.
Typical doses are 25–50 mg daily for heart failure or resistant hypertension (sometimes up to 100 mg), 100–200 mg for short-term testing/treatment of hyperaldosteronism, and 50–100 mg daily for acne or hirsutism. Dosing is individualized based on response and labs.
Yes, but men are more prone to endocrine side effects like gynecomastia, decreased libido, and erectile dysfunction, especially at higher doses. If these occur, dose reduction or switching to eplerenone may help.
It can reduce water weight by promoting fluid loss, but it does not cause fat loss. Any rapid weight drop is usually due to reduced edema, not a change in body fat.
Yes. Excessive diuresis can lead to dehydration, dizziness, or low blood pressure, especially in hot weather, with illness, or when combined with other blood pressure drugs or alcohol. Hydrate appropriately and report persistent lightheadedness.
Yes, its antiandrogen effects can reduce hormonal acne and excessive hair growth, particularly in women with androgen-sensitive conditions. It is often combined with topical therapies, and results take weeks to months.
Limit high-potassium foods and salt substitutes containing potassium unless advised otherwise, and avoid dehydration. A heart-healthy, lower-sodium diet supports blood pressure and fluid control.
Moderate alcohol can intensify dizziness and low blood pressure and worsen dehydration. If you drink, do so sparingly, avoid binge drinking, and hydrate; skip drinking on days you feel lightheaded or unwell.
It is generally avoided in pregnancy due to antiandrogenic effects that could affect fetal development, particularly in male fetuses. If you could become pregnant, use effective contraception and discuss safer alternatives with your clinician.
Spironolactone appears in low amounts in breast milk and is generally considered compatible with breastfeeding, but data are limited. Monitor the infant for poor feeding or dehydration and discuss risks and benefits with your clinician.
Your surgical team may advise holding Aldactone the morning of surgery to reduce risks of low blood pressure, dehydration, or high potassium. Follow pre-op instructions and ensure recent potassium and kidney function are reviewed.
Illness can raise the risk of dehydration and kidney injury. Temporarily hold Aldactone and potassium-raising drugs, maintain fluids, and contact your clinician for guidance and possible lab checks before restarting.
Yes, but you are more prone to dehydration and low blood pressure. Hydrate well, avoid excessive heat, and pause exercise if you feel dizzy or weak.
Generally no, because they can cause dangerous hyperkalemia. Only use potassium products if specifically directed and monitored by your clinician.
Both are mineralocorticoid receptor antagonists; Aldactone is less expensive and widely used, while eplerenone is more selective with fewer endocrine side effects (like gynecomastia) but often costs more. Both help in heart failure and resistant hypertension, with similar monitoring needs.
Aldactone blocks aldosterone and treats conditions like heart failure and hyperaldosteronism; amiloride blocks epithelial sodium channels without antiandrogen effects. Amiloride may be preferred if endocrine side effects are a concern, but it is less proven in heart failure.
Both are potassium-sparing diuretics, but Aldactone is an aldosterone antagonist with proven benefits in heart failure and hyperaldosteronism. Triamterene is often combined with a thiazide for hypertension and edema but lacks the mortality data seen with Aldactone in heart failure.
Hydrochlorothiazide is typically first-line for hypertension, causing sodium and water loss but can lower potassium. Aldactone is often added for resistant hypertension and tends to raise potassium; combining them can balance electrolytes with careful monitoring.
Furosemide (a loop diuretic) is stronger for rapid fluid removal in edema and heart failure exacerbations but wastes potassium. Aldactone is milder, potassium-sparing, and improves outcomes in chronic heart failure; they are frequently used together.
Both improve outcomes in reduced ejection fraction with heart failure or diabetes after MI. Eplerenone may be favored if gynecomastia or sexual side effects are problematic, while Aldactone is more affordable and widely available.
Chlorthalidone is a potent thiazide-like diuretic that often forms the backbone of hypertension therapy. Aldactone is highly effective as an add-on in resistant cases, especially if aldosterone excess is suspected; together they can be complementary with electrolyte monitoring.
Both block mineralocorticoid receptors, but finerenone is nonsteroidal and has strong evidence for slowing chronic kidney disease progression in type 2 diabetes with less endocrine side effects. Aldactone is not as well studied in diabetic CKD but is effective for heart failure and hyperaldosteronism.
The combo offers blood pressure control with potassium-sparing offset of thiazide-induced losses. Aldactone may be more effective in resistant hypertension and provides benefits in heart failure; choice depends on indication, side effects, and lab results.
They contain the same active ingredient and are considered therapeutically equivalent. Most patients do equally well on generic spironolactone at lower cost.
Adding Aldactone to a loop diuretic (often in a 100:40 mg ratio of spironolactone to furosemide) improves sodium balance and ascites control compared with loop alone. This combo also helps maintain potassium within range.
Bumetanide and torsemide are potent loop diuretics for rapid diuresis in edema and heart failure flares. Aldactone is weaker as a diuretic but improves survival in chronic heart failure and spares potassium; they are often combined for synergistic effect.
Both prevent thiazide-induced hypokalemia. Amiloride has fewer endocrine effects, while Aldactone may provide added blood pressure benefits in resistant hypertension; selection is individualized based on side effects and comorbidities.
