Danazol used in endometriosis produces therapeutic benefit but commonly causes weight gain, acne and voice deepening. Its pharmacological class and basis for these adverse effects is:

• A Pure GnRH agonist producing downregulation of pituitary receptors
• B Progestogen with potent glucocorticoid cross-reactivity
• C Antioestrogen acting as a competitive antagonist at uterine oestrogen receptors
• D Attenuated androgen with antigonadotropic and mild anabolic activity ✓

Explanation

Danazol is an attenuated (weakly androgenic) 17 alpha-ethinyl testosterone derivative. It suppresses the midcycle gonadotropin surge and produces a hypo-oestrogenic environment hostile to endometrial implants, while its residual androgenicity accounts for hirsutism, acne, weight gain and irreversible voice change. GnRH agonists such as leuprolide cause similar hypo-oestrogenism without androgenic effects, which separates option A. It is neither an antioestrogen like clomiphene nor a glucocorticoid-cross-reacting progestogen.

Reference: KD Tripathi Essentials of Medical Pharmacology, 8th ed.

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