Add an antiandrogen after six months of inadequate OC response
STEP 1 — Gather Information
Document baseline Ferriman–Gallwey (FG) score, current OC formulation and dose, duration of OC monotherapy, patient‑reported hirsutism distress, menstrual regularity, and contraceptive use. Action: Record these data and proceed to step 2.
STEP 2 — Rule In / Rule Out
Is the patient on OC monotherapy for at least 6 months with inadequate or suboptimal hirsutism improvement?
- Yes: Proceed to step 3.
- No: Continue OC monotherapy and reassess response in 3 months. Decision: End of algorithm for now.
STEP 3 — Classify or Stratify
Classify hirsutism severity using FG score (mild 8‑15, moderate 16‑25, severe >25) and patient‑important distress level. Also confirm need for effective contraception if of child‑bearing potential. Action: Assign severity tier and contraception status, then move to step 4.
STEP 4 — Decide
Add an antiandrogen (e.g., spironolactone 100‑200 mg daily in divided doses, finasteride 2.5‑5 mg daily, or dutasteride) while ensuring effective contraception; avoid flutamide due to hepatotoxicity risk. Decision: Prescribe selected antiandrogen and schedule follow‑up in 3 months to assess response.
Clinical Guardrails / Mimics / Pitfalls
Do not initiate antiandrogen monotherapy without reliable contraception because of teratogenic risk; avoid flutamide unless hepatotoxicity monitoring is in place; do not add antiandrogen before 6 months of OC monotherapy unless there is rapid progression or virilization; monitor liver enzymes if flutamide is ever considered.
Concrete Clinical Example
A 24‑year‑old woman with PCOS has been on EE 20 mcg + levonorgestrel OC for 8 months, FG score 18, reports persistent facial hair distress despite shaving. She uses condoms for contraception. According to the guideline, add spironolactone 100 mg BID and continue OC; reassess FG score and symptoms in 3 months.
Source: Evaluation and Treatment of Hirsutism in Premenopausal Women: An Endocrine Society Clinical Practice Guideline, Endocrine Society, 2018, DOI:10.1210/jc.2018-00241
TODO: consider adding scripts/calc.py for the endo-hirsutism-add-antiandrogen-after-6months calculator