Is spironolactone (an aldosterone antagonist) associated with hirsutism (abnormal female hair growth)?

From the Guidelines

Spironolactone is conditionally recommended for the treatment of abnormal female hair growth, such as hirsutism, due to its ability to decrease testosterone production and competitively inhibit androgen receptors, as supported by moderate certainty evidence from recent studies 1. The medication works by blocking the effects of androgens, such as testosterone and dihydrotestosterone, which are hormones that can contribute to excessive hair growth in women.

• The typical dosage of spironolactone for this condition is 50-200 mg daily, taken in divided doses, as shown in studies 1.
• Treatment with spironolactone should be continued for at least 6 months to see significant improvement in hair growth, as hair growth cycles are slow to respond.
• Common side effects of spironolactone include menstrual irregularities, breast tenderness, and increased urination, as reported in studies 1.
• It is essential to monitor potassium levels during treatment with spironolactone, especially in older patients or those with certain medical conditions, such as hypertension, diabetes, or kidney disease, due to its potassium-sparing diuretic properties 1.
• Spironolactone is contraindicated during pregnancy due to the potential risk of feminization of male fetuses, and effective contraception is necessary for women of childbearing age 1.
• For optimal results, spironolactone may be combined with cosmetic hair removal methods, such as laser therapy or electrolysis, and lifestyle modifications, such as maintaining a healthy weight, can also help manage hirsutism 1.

From the Research

Spironolactone and Abnormal Female Hair Growth

• Spironolactone has been used as a primary medical treatment for hirsutism, which is characterized by excessive hair growth in women, for over 30 years 2.
• The drug has been shown to reduce adrenal androgen production and exert competitive blockade on androgen receptors in target tissues, leading to a decrease in hair growth 3.
• Studies have demonstrated that spironolactone is effective in reducing hair growth in women with hirsutism, with significant decreases in hair shaft diameter and daily hair volume production observed in treated patients 3, 4.
• Comparison studies have been conducted to evaluate the efficacy of spironolactone versus other anti-androgen therapies, such as flutamide, in the treatment of hirsutism 5, 6.
• While flutamide has been shown to be superior to spironolactone in some studies, spironolactone remains a commonly used and effective treatment option for hirsutism, particularly when used in combination with other therapies such as finasteride or ethinyloestradiol/cyproterone acetate 4, 6.

Mechanism of Action

• Spironolactone's anti-androgen effects are thought to be mediated by its ability to block androgen receptors in target tissues, as well as its ability to reduce adrenal androgen production 2, 3.
• The drug's mechanism of action is complex and involves multiple pathways, including the inhibition of 5-alpha-reductase, an enzyme involved in the conversion of testosterone to dihydrotestosterone (DHT) 2.

Clinical Efficacy

• Spironolactone has been shown to be effective in reducing hair growth in women with hirsutism, with significant improvements in hirsutism scores and quality of life observed in treated patients 3, 4, 6.
• The drug is generally well-tolerated, with common side effects including menstrual irregularities, breast tenderness, and dizziness 3, 4, 6.