Dienogest, a 19-nortestosterone derivative used in endometriosis, has a unique combination of properties that distinguishes it from older progestogens. Which of the following correctly characterises dienogest's pharmacological profile?

• A Selective progestogenic activity with anti-androgenic and antigonadotrophic properties; acts locally on endometriotic cells to induce apoptosis and suppress aromatase ✓
• B High androgenic and antiestrogenic activity; suppresses FSH via negative feedback
• C Acts as a GnRH receptor partial agonist; causes initial flare then sustained suppression
• D Pure antiprogestogen with no androgenic activity; used only after surgical debulking

Explanation

Dienogest is a synthetic progestogen with a unique profile: high selective progestogenic activity, significant anti-androgenic properties (unlike older 19-nortestosterone derivatives), and moderate antigonadotrophic effect. It acts locally on endometriotic implants to suppress aromatase (reducing local oestrogen production), promote apoptosis of endometriotic cells, and inhibit NFκB-mediated inflammation. Unlike GnRH analogues, it maintains partial oestrogen levels that protect bone density, avoiding hypo-oestrogenic side effects. It is approved for long-term use in endometriosis.

Reference: Shaw's Textbook of Gynaecology, 17th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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