A 36-year-old woman with Stage III endometriosis (revised ASRM) has persistent dysmenorrhea despite 6 months of continuous combined oral contraceptive therapy. She has no fertility desire. Her pain significantly affects daily function. Which pharmacotherapy works by inhibiting aromatase to reduce local oestrogen production within endometriotic lesions?

• A Letrozole 2.5 mg daily ✓
• B Medroxyprogesterone acetate 150 mg intramuscular every 3 months
• C Dienogest 2 mg daily
• D Danazol 200 mg twice daily

Explanation

Letrozole is a third-generation aromatase inhibitor that blocks the conversion of androgens to oestrogens, including local oestrogen synthesis within endometriotic implants via ectopic aromatase expression. It is used off-label as second-line or add-back therapy for refractory endometriosis pain. Dienogest and medroxyprogesterone are progestins acting on progesterone receptors. Danazol works by suppressing pituitary gonadotropins and creating a hyperandrogenic state, not via aromatase inhibition.

Reference: Endocrinology of Pregnancy and Reproduction (Strauss and Barbieri), 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.