What is the recommended dose of spironolactone for treating hirsutism in women of reproductive age?

Recommended Spironolactone Dosing for Hirsutism

Start spironolactone at 100 mg daily in the evening for treating hirsutism in women of reproductive age, with the option to increase to 150 mg daily after 3 months if response is inadequate, though doses of 50-100 mg daily are equally effective with substantially fewer side effects. 1

Initial Dosing Strategy

The American College of Obstetricians and Gynecologists recommends 100-150 mg daily as the standard effective dose range, achieving improvement in 85% of patients and complete remission in 55%. 1 However, the evidence strongly supports starting lower:

• Begin with 100 mg daily in the evening as the typical starting dose 2, 1
• Alternative lower starting dose of 50 mg twice daily (days 4-21 of menstrual cycle) significantly reduces side effects while maintaining efficacy 3, 4
• Lower doses (50-75 mg daily) demonstrate excellent clinical response in 58-61% of patients with minimal side effects 4, 5, 6

Dose Escalation Protocol

If inadequate response after 3 months, increase in 25-50 mg increments every 3 months, with maximum dose typically 200 mg daily. 2

• Expect initial response at approximately 3 months on average 2, 1
• Maximum therapeutic benefit requires 5-6 months of treatment 2
• In patients with inadequate response at 100 mg/day, increasing to 150 mg/day can lead to additional improvement 2
• Doses above 200 mg daily should not be exceeded routinely, as side effects increase disproportionately to therapeutic benefit 2

Critical Combination Therapy

Always combine spironolactone with a combined oral contraceptive (COC) for optimal results. 1 This combination approach:

• Represents the most effective treatment strategy per the American College of Obstetricians and Gynecologists 1
• Regulates menses and prevents pregnancy (spironolactone is pregnancy category C) 2, 1
• Minimizes menstrual irregularities, the most common side effect 2
• Can safely include drospirenone-containing COCs without causing hyperkalemia 2, 1

Side Effect Profile and Management

Menstrual irregularities are the major dose-limiting side effect, occurring in 22-56% of patients depending on dose. 1, 3

• At 200 mg twice daily (400 mg total), 56% developed intolerable metrorrhagia with 14-day cycles 3
• At 100 mg daily, menstrual irregularities occur in 22-40.6% of patients 1
• At 50 mg twice daily, only 20% developed metrorrhagia 3
• Other side effects include diuresis (29%), breast tenderness (17%), breast enlargement, and decreased libido 2, 1

Monitoring Requirements

Routine potassium monitoring is NOT required in young, healthy women without comorbidities. 2, 1

However, monitor potassium at baseline, during therapy, and after dose increases in:

• Older patients 2, 1
• Patients with renal, cardiovascular, or hepatic disease 1
• Those taking ACE inhibitors, ARBs, NSAIDs, or digoxin 1

Common Pitfall to Avoid

The most critical error is starting at excessively high doses (200 mg twice daily), which causes intolerable menstrual irregularities in over half of patients, leading to treatment discontinuation. 3 The evidence clearly demonstrates that lower doses (50-100 mg daily) provide equivalent efficacy with dramatically fewer side effects, making them the preferred starting point for most patients. 4, 5, 6

Adjunctive Therapy

Laser hair removal is an essential adjunct to systemic therapy, requiring multiple treatments for optimal results. 1 Additionally, weight loss of as little as 5% of total body weight significantly improves hirsutism through testosterone reduction. 1