How to prescribe spironolactone for a female patient of childbearing age with hirsutism, possibly due to polycystic ovary syndrome (PCOS)?

How to Prescribe Spironolactone for Hirsutism in Women of Childbearing Age

Prescribe spironolactone 50-200 mg daily in combination with a combined oral contraceptive pill (OCP), never as monotherapy in women of reproductive potential, and counsel patients that visible improvement requires 6-12 months of continuous treatment. 1

Mandatory Combination Therapy

• Spironolactone must always be combined with reliable contraception in sexually active women of childbearing age because it is pregnancy category C and carries risk of feminization of male fetuses. 1
• Combined oral contraceptives serve dual purposes: they provide essential contraception and enhance therapeutic efficacy by suppressing ovarian androgen secretion and increasing sex hormone-binding globulin. 1, 2
• Any combined OCP formulation is effective, though specific formulations studied include cyproterone acetate 2 mg/ethinylestradiol 35 μg or drospirenone 3 mg/ethinylestradiol 20 μg. 1

Dosing Protocol

• Start spironolactone at 50-100 mg daily and titrate up to 200 mg daily based on response and tolerability. 1
• The medication can be taken with or without food, but should be taken consistently with respect to food. 3
• Higher doses (100-200 mg daily) have been shown to produce clear beneficial effects on facial hair growth in moderate to severe hirsutism. 4

Pre-Treatment Assessment

• Obtain baseline serum potassium, renal function (eGFR), and blood pressure before initiating therapy. 3
• Screen for conditions that increase hyperkalemia risk: chronic kidney disease, diabetes, hypertension, or concomitant use of ACE inhibitors, ARBs, or NSAIDs. 1, 3
• Document baseline hirsutism severity using Ferriman-Gallwey scoring to track treatment response. 5

Monitoring Requirements

• Monitor serum potassium within 1 week of initiation or dose titration, then regularly thereafter. 3
• More frequent potassium monitoring is required in patients with impaired renal function, older patients, those with diabetes or hypertension, or those taking medications that increase potassium (ACE inhibitors, ARBs, NSAIDs, potassium supplements). 1, 3
• Monitor serum electrolytes, uric acid, and blood glucose periodically, as spironolactone can cause hyponatremia, hypomagnesemia, hypocalcemia, hypochloremic alkalosis, and hyperglycemia. 3
• Monitor volume status and renal function periodically to detect hypotension and worsening renal function. 3

Expected Timeline and Outcomes

• Counsel patients that improvement takes 6-12 months due to hair growth cycles, and treatment must continue long-term to maintain androgen suppression. 1
• Regression of hirsutism in terms of hair diameter, density, and growth rate becomes noticeable within 2 months, with maximal effect at 6 months. 4
• Studies show 30-40% improvement in facial and body hirsutism with spironolactone 100 mg twice daily, with threefold reduction in frequency of local hair removal treatments. 6
• Medical therapy is palliative rather than curative; hirsutism will recur if treatment is discontinued. 1

Common Side Effects

• Menstrual irregularities (which are mitigated by concurrent OCP use) 1, 6
• Diuresis (typically limited to first few days of treatment) 1, 4
• Breast tenderness 1
• Mild nausea, vomiting, or diarrhea 5
• Fatigue, acne aggravation, or spotting (less common) 7

Adjunctive Therapies

• Combine medical management with mechanical hair removal methods (laser, electrolysis, waxing) for optimal results, as drugs only partially affect terminalized hairs already present. 1
• Consider eflornithine hydrochloride cream as adjunctive topical therapy, the only FDA-approved topical treatment specifically for hirsutism. 1
• Prescribe foundational lifestyle modification targeting 5% weight loss through energy deficit of 500-750 kcal/day and at least 150 minutes/week of moderate-intensity exercise, which significantly improves androgen levels and hirsutism in PCOS. 1, 2

Critical Pitfalls to Avoid

• Never prescribe antiandrogens without concurrent contraception in women of reproductive potential. 1
• Do not expect rapid results; failure to set realistic expectations about the 6-12 month timeline leads to premature discontinuation. 1
• Do not prescribe spironolactone to patients with hyperkalemia (serum potassium > 5.0 mEq/L) or severe renal impairment (eGFR < 30 mL/min/1.73 m²). 3
• Do not overlook potassium monitoring in high-risk patients, as hyperkalemia is the most serious adverse effect. 3
• Do not neglect metabolic screening in PCOS patients, as they require comprehensive evaluation including fasting glucose, lipid profile, and regular screening for type 2 diabetes and cardiovascular disease. 2

Alternative Antiandrogen Options

• Finasteride 5 mg daily can be considered when spironolactone is contraindicated or not tolerated, but must also be combined with oral contraceptives due to severe teratogenic risk to male fetuses. 8
• Finasteride should not be used as monotherapy and patients should not donate blood until 6 months after the last dose. 8