Danazol used in the management of endometriosis produces its therapeutic effect primarily by which mechanism?

• A Selective agonist action at progesterone receptors causing decidualisation of implants
• B Competitive blockade of estrogen receptors in endometrial tissue
• C Suppression of pituitary gonadotropin secretion creating a hypoestrogenic state, with weak androgenic activity ✓
• D Inhibition of prostaglandin synthesis within ectopic endometrium

Explanation

Danazol is a synthetic androgen derived from ethisterone. It suppresses the midcycle surge of LH and FSH, abolishing cyclical ovarian estrogen production and producing an anovulatory, hypoestrogenic environment in which endometriotic implants atrophy. It also mildly inhibits multiple steroidogenic enzymes and carries androgenic side effects such as hirsutism, acne and voice deepening. It is neither a progesterone agonist nor an estrogen receptor blocker, which excludes the other options.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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