Spironolactone (Aldactone Generic)
Spironolactone is the generic name and product for the aldosterone antagonist diuretic used in heart failure, resistant hypertension, ascites and several androgen-related conditions in women. Originally marketed as Aldactone, with widely available authorised generics.
- Active ingredients
- Spironolactone
- Manufacturer
- Various generics
- Dosage forms
- tablet
- Available dosages
- 25mg, 50mg, 100mg
- Category
- Diuretics
What is it?
Spironolactone is the generic form of the aldosterone receptor antagonist originally marketed as Aldactone since the 1960s. It has been on the WHO Essential Medicines List for decades and authorised generics have been widely available in most regulated markets for years. The product is used across cardiology, hepatology, nephrology, dermatology and gynaecology — making it one of the most versatile generic medications in the formulary.
Active ingredients
Each spironolactone tablet contains 25mg, 50mg or 100mg of spironolactone, an aldosterone receptor antagonist with secondary anti-androgen activity. The active substance is identical between branded Aldactone and authorised generics, with bioequivalence required by regulatory standards. Most clinical use today is on the authorised generic at significantly lower cost than the originator.
Forms and dosages
Spironolactone is supplied as round, film-coated tablets in 25mg, 50mg and 100mg strengths. Dosing varies markedly by indication: heart failure starts at 12.5–25mg daily and rarely exceeds 50mg; primary hyperaldosteronism may use 100–400mg daily; dermatological use in women is typically 50–200mg daily. Tablets can be taken with or without food, although food slightly improves absorption.
Indications
Spironolactone is approved for heart failure with reduced ejection fraction, primary hyperaldosteronism, resistant hypertension, oedema in cirrhosis or nephrotic syndrome, and certain potassium-loss states. Off-label uses include female pattern hair loss, hirsutism, polycystic ovary syndrome and acne in women. According to clinical guidelines, it is a first-line add-on in heart failure and a strong third-agent in resistant hypertension.
How it works
Spironolactone competitively blocks the aldosterone (mineralocorticoid) receptor in the distal tubule, reducing sodium reabsorption and potassium excretion. The diuretic effect develops over days as aldosterone-mediated sodium retention is unwound. The anti-androgen effect on skin and hair follicles reflects weak androgen-receptor antagonism by spironolactone and its active metabolite canrenone. Clinical effect on hair and acne develops over months.
Frequently asked questions
Why is spironolactone prescribed for acne in women? ▾
Spironolactone has anti-androgen activity that reduces sebum production and the hormonal driver of acne. In adult women with hormonal acne, doses of 50–200mg daily can produce meaningful improvement over 3–6 months. According to dermatology guidelines, it is used off-label in women only and is contraindicated in pregnancy because of feminisation risk to a male fetus.
What labs do I need on spironolactone? ▾
Serum potassium and creatinine are checked at baseline, within 1–2 weeks of starting or any dose increase, and periodically thereafter. According to the prescribing information, hyperkalaemia is the main risk and is amplified by ACE inhibitors, ARBs, NSAIDs and renal impairment. Persistent hyperkalaemia warrants dose reduction or alternative.
Will spironolactone make me feel different from other diuretics? ▾
Spironolactone is gentler than loop diuretics like furosemide. Most users notice mild increased urination in the first weeks, which usually settles. Anti-androgen effects can include reduced libido in men and breast tenderness in both sexes, particularly at higher doses.
Can I take spironolactone with my heart medications? ▾
Yes, spironolactone is commonly combined with ACE inhibitors, ARBs, beta-blockers and other heart failure therapy. The combination requires more careful potassium monitoring but is the standard of care for symptomatic heart failure with reduced ejection fraction. The prescriber adjusts doses to keep potassium and creatinine in range.
Is spironolactone the same as Aldactone? ▾
Yes — Aldactone is the originator brand and generic spironolactone tablets contain the same active ingredient. Authorised generics have demonstrated bioequivalence to Aldactone at the standard 25/50/100mg strengths. The generic is significantly cheaper and clinically equivalent in nearly all cases.
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The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.