Aldactone

Spironolactone

Formulated to alleviate fluid retention, indicated to support blood pressure management and target mineralocorticoid receptors.

Active ingredient
Spironolactone
Supply
Pharmacy
Route
Oral use
Form
Film-coated tablet
Strengths
25 · 100mg

Aldactone details

Therapeutic class
Diuretic
Pharmacological class
Aldosterone Antagonist
Known off-label uses
hirsutism
Contraindications
hypersensitivity to spironolactone; Addison's disease; hyperkalaemia; anuria
Minor side effects
headache; gastrointestinal disturbances; drowsiness
Moderate side effects
gynaecomastia; menstrual irregularities; hyponatraemia
Dosage forms
Film-coated tablet
Administration route
Oral use
Supply category
Pharmacist only, dispensed without a prescription
Manufacturer
Pfizer
Onset Time
2–4 days
Duration
2–3 days
Storage instructions
Store below 25°C, protected from light.
Drug interactions
potassium-sparing diuretics; ACE inhibitors
Age restrictions
Use with caution in elderly patients.
Pregnancy and breastfeeding
Use only if benefit outweighs risk.
Precautions and warnings

regular blood monitoring of potassium levels required; avoid excessive salt intake; may affect urination frequency

Serious side effects

severe hyperkalaemia, requires immediate medical attention; arrhythmia, requires immediate medical attention

Patient summary

Formulated to alleviate fluid retention, indicated to support blood pressure management and target mineralocorticoid receptors.

Mechanism of action

It serves as a competitive antagonist of aldosterone. By blocking the effects of aldosterone in the distal renal tubules, it increases sodium and water excretion while retaining potassium, which helps reduce excess fluid and pressure.

Where this medicine is registered

  • Singapore
  • Hong Kong
  • Thailand
  • Malaysia
  • Philippines
  • Indonesia
  • Taiwan
  • South Korea
  • Japan
  • Australia
  • New Zealand
  • UAE
  • South Africa

About Aldactone

Aldactone is the primary brand name for spironolactone, a well-established medication used in the management of hypertension, oedema and heart failure. Supplied as a tablet by Pfizer, options include strengths of 25mg and 100mg. Many patients requiring this type of therapy view the drug as a foundational component of their ongoing treatment.

Buying Aldactone online

Aldactone is currently registered across 14 markets, including South Korea, Japan and the UAE, with consistent availability throughout Singapore, Hong Kong and Thailand. While the original brand remains a preferred choice for many, generic versions containing spironolactone are often produced in India to provide a significantly more affordable option. This makes the treatment accessible for expats and those living in regions where local medicine supply may be restricted.