Spironolactone

Spironolactone, marketed under the brand name Aldactone among others, is a medication primarily used to treat fluid build-up due to heart failure, liver scarring, or kidney disease. Other uses include high blood pressure, low blood potassium that does not improve with supplementation, early puberty, excessive hair growth in women, and as a component of hormone replacement therapy for trans women. It is taken by mouth.

Common side effects include electrolyte abnormalities particularly high blood potassium, nausea, vomiting, headache, a rash, and a decreased desire for sex. In those with liver or kidney problems extra care should be taken. Spironolactone has not been well studied in pregnancy and should not be used to treat high blood pressure of pregnancy. It is a steroid that blocks mineralocorticoid receptors. It also blocks androgen, and blocks progesterone. It belongs to a class of medications known as potassium-sparing diuretics.

Spironolactone was introduced in 1959. It is on the World Health Organization's List of Essential Medicines, the most important medication needed in a basic health system. It is available as a generic medication. The wholesale cost as of 2014 is between 0.02 and 0.12 USD per day. In the United States it costs about 0.50 USD per day.