What is the role of Aldactone (spironolactone) in treating facial hair?

Spironolactone for Facial Hair: Efficacy, Dosing, and Side Effects

Spironolactone is an effective treatment for reducing unwanted facial hair in women, with doses ranging from 50-200 mg daily showing significant reduction in hair growth through its potent anti-androgenic properties. 1, 2

Mechanism of Action

• Spironolactone works as an aldosterone receptor antagonist with potent anti-androgenic activity through multiple mechanisms:
  • Decreases testosterone production 1, 2
  • Competitively inhibits binding of testosterone and dihydrotestosterone to androgen receptors in the skin 1, 3
  • May inhibit 5-alpha-reductase and increase steroid hormone-binding globulin 1
  • Reduces sebum production through blocking androgen receptors on sebocytes 2

Dosing and Efficacy

• Typical dosing for hirsutism (unwanted facial hair):

  • Starting dose: 100 mg/day, typically taken in the evening 2
  • Effective dose range: 50-200 mg daily 2, 4
  • Higher doses (200 mg/day) show greater efficacy but also increased side effects 1, 4

• Efficacy timeline:

  • Initial improvement may be noticeable within 2 months 4
  • Maximal effect typically observed at 6 months of treatment 4
  • Continuous treatment required to maintain results 3, 4
  • Several months of treatment typically needed to reach full effectiveness 1, 2

• Clinical outcomes:

  • Regression of facial hair in terms of diameter, density, and growth rate 4, 5
  • Studies show hair shaft diameter decreases of 19-30% 5
  • 95% of patients with moderate to severe hirsutism show improvement 4

Side Effects and Monitoring

• Common side effects (dose-related):

  • Menstrual irregularities (15-30% of patients) 1, 2
  • Diuresis (29%), especially in first few days of treatment 1, 4
  • Breast tenderness (3-5%) and breast enlargement 1, 2
  • Dizziness (3-4%), headache (2%), fatigue (1-2%) 1, 2
  • Nausea (2-4%) and polyuria (1-2%) 1, 2

• Hyperkalemia risk:

  • Rare in young, healthy women with normal renal, hepatic, and adrenal function 1
  • Routine potassium monitoring is not required in young, healthy women 1
  • Potassium monitoring recommended for:
    • Older patients 1, 2
    • Patients with renal insufficiency or heart failure 1
    • Patients taking medications like ACE inhibitors, angiotensin receptor blockers, NSAIDs, or digoxin 1

Important Considerations and Contraindications

• Gender considerations:

  • Not used in men due to risk of feminization (gynecomastia) 3, 6, 7
  • Studies in men with facial hair were discontinued due to development of gynecomastia 1

• Pregnancy:

  • Pregnancy category C - not recommended during pregnancy 1, 2
  • Animal studies have shown feminization of male fetuses 1
  • Concomitant use of a combined oral contraceptive (COC) is often recommended to prevent pregnancy 1, 2

• Combined therapy:

  • Using spironolactone with combined oral contraceptives:
    • Helps regulate menstrual irregularities 1, 2
    • Provides contraception (important due to pregnancy risks) 1, 2
    • Can be safely used with drospirenone-containing COCs without increased hyperkalemia risk 1

• Absolute contraindications:

  • Pregnancy 2
  • Acute renal failure 2
  • Addison's disease 2
  • Hyperkalemia 2
  • Anuria 2
  • Significant renal impairment 2
  • Concomitant use of eplerenone or triamterene 2

Clinical Pearls

• Spironolactone has been used off-label for hirsutism for over 30 years with a long-term safety profile 3, 7
• Equally effective for hirsutism in women with polycystic ovary syndrome and idiopathic hirsutism 4
• Patients should be counseled that full effects take several months to develop 1, 4
• Spironolactone has a black box warning due to tumorigenicity in animal studies at doses >100 times clinical doses, but large cohort studies with over 30 million person-years of follow-up have not confirmed such risks in typical clinical practice 1