**Question:** All are anti-androgens except

A. Spironolactone
B. Flutamide
C. Goserelin
D. Cyproterone acetate

**Correct Answer:** C. Goserelin

**Core Concept:** Anti-androgens are medications that block the effects of androgens (male sex hormones) in the body. Androgens play a role in the development of male characteristics, such as facial hair, deepening of the voice, and increased muscle mass. Anti-androgens can be classified into two main types: Selective Androgen Receptor Modulators (SARMs) and Selective Androgen Receptor Antagonists (SARAs).

**Why the Correct Answer is Right:**
Goserelin belongs to the class of drugs known as Luteinizing Hormone-Releasing Hormone (LHRH) antagonists. LHRH is a hormone that stimulates the pituitary gland to produce and release luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which then stimulate the testes to produce testosterone. By blocking LHRH, goserelin inhibits the production of LH and FSH, indirectly decreasing testosterone levels. As a result, goserelin works as an anti-androgen by reducing the effect of androgens in the body.

**Why Each Wrong Option is Incorrect:**

A. Spironolactone is a potassium-sparing diuretic used primarily to treat hypertension and edema. While it does have anti-androgenic effects, it primarily works as a potassium-sparing diuretic and not as a direct anti-androgen like Goserelin.

B. Flutamide is an anti-androgen used to treat prostate cancer. It competitively inhibits the binding of androgens to their receptors, thereby preventing their action. However, Goserelin works as a LHRH antagonist, which is a different mechanism compared to Flutamide.

C. Goserelin is a LHRH antagonist, as explained above. In contrast, Cyproterone acetate is an anti-androgen that acts by blocking the binding of androgens to their receptors and inhibiting their action.

D. Flutamide is primarily used as an anti-androgen in the treatment of prostate cancer. It competetively inhibits the binding of androgens to their receptors, preventing their action. In contrast, Goserelin works as a LHRH antagonist, which is a different mechanism compared to Flutamide.

**Clinical Pearl:** The distinction between SARMs (Selective Androgen Receptor Modulators) and SARMs (Selective Androgen Receptor Modulators) is crucial in understanding their mechanisms of action and therapeutic applications. SARMs are used for treating conditions like osteoporosis, muscle wasting, and breast cancer, while SARMs are used in conditions like prostate cancer.