Spironolactone: Price, Dosage & Where to Buy

Spironolactone is an aldosterone antagonist and potassium-sparing diuretic medicine. It is most commonly prescribed to help manage fluid retention and symptoms associated with heart failure, while also being used for high blood pressure and certain hormone-related conditions. Spironolactone has been available as a generic medicine since 1986-07-23 and requires a prescription in the United Kingdom.

Spironolactone is used with other heart failure treatments for NYHA Class III-IV heart failure with reduced ejection fraction. It can help manage oedema, increase survival and reduce the need for hospitalisation for heart failure.

It is also used as add-on treatment for hypertension when other medicines have not controlled blood pressure adequately. Lowering blood pressure reduces the risk of cardiovascular events, primarily strokes and myocardial infarctions.

The medicine manages oedema associated with liver cirrhosis when fluid and sodium restriction have not been enough. It may also be used for oedema associated with nephrotic syndrome when treatment of the underlying disease, fluid and sodium restriction, and other diuretics have produced an inadequate response.

Spironolactone is also used for primary hyperaldosteronism, including short-term treatment before surgery and long-term maintenance when surgery is unsuitable or when adrenal hyperplasia is present.

Spironolactone blocks the effects of aldosterone, a hormone that encourages the kidneys to retain sodium and water. By reducing aldosterone activity, the kidneys can remove more sodium and water in urine, which can help reduce fluid build-up and lower blood pressure.

Unlike some diuretics, spironolactone has a potassium-sparing effect because it reduces aldosterone-driven potassium loss. This means potassium levels can become too high, particularly when kidney function is impaired or when spironolactone is combined with other medicines or supplements that increase potassium. The medicine also has anti-androgenic and other hormone-related effects, which help explain some reproductive and breast-related adverse effects.

The label lists oral suspension containing 25 mg/5 mL and oral tablets containing 25 mg, 50 mg, and 100 mg. The label lists heart failure treatment initiated at 25 mg once daily. The label lists hypertension treatment initiated at 25 to 100 mg daily, given as a single or divided dose.

The label lists oedema treatment initiated in hospital, with a recommended initial daily dose of 100 mg in single or divided doses and a range of 25 to 200 mg daily. The label lists primary hyperaldosteronism treatment at 100 to 400 mg daily in preparation for surgery.

The usual starting dose is determined by the condition, kidney function, serum potassium, response and tolerability. The label states that tablets can be taken with or without food, consistently in relation to food.

A missed dose means the planned dose was not taken at the expected time. General pharmacy practice is to take the missed dose when remembered unless it is nearly time for the next scheduled dose. If it is nearly time for the next dose, the missed dose is generally omitted and the regular schedule resumed.

Double dosing is not advised. A pharmacist or doctor can provide advice if several doses are missed or if symptoms of dehydration, dizziness or confusion occur.

The label advises avoiding spironolactone during pregnancy because its anti-androgenic properties and animal findings indicate a potential risk to sex differentiation of a male fetus. Limited published case reports and case series did not show an association with major malformations or other adverse pregnancy outcomes, but the potential fetal risk remains relevant.

Discuss pregnancy or plans for pregnancy with a doctor or pharmacist. Spironolactone is not present in breastmilk, although low amounts of its active metabolite, canrenone, have been found; long-term effects on a breastfed infant are unknown.

Store at 20° to 25°C. Keep the product in a tight, light-resistant container to maintain quality. Protect it from unsuitable storage conditions and keep it as directed on the label.