**Question:** Drug causing hirsuitism and gynaecomastia

**Core Concept:** Hirsuitism and gynaecomastia are clinical manifestations resulting from the excess production and action of female sex hormones in males.

**Why the Correct Answer is Right:** Hirsuitism refers to excessive hair growth on the face, body, and/or genital area in females, while gynaecomastia is the enlargement of the breast tissue in males. These symptoms are commonly caused by the use of anabolic steroids, which are synthetic derivatives of testosterone. Anabolic steroids promote the conversion of androgens (male sex hormones) to estrogens (female sex hormones) via the enzyme aromatase. This increased estrogen production leads to the clinical manifestations mentioned.

**Why Each Wrong Option is Incorrect:**

A. Oestrogens: Although oestrogens are female sex hormones, they are not the primary cause of hirsuitism and gynaecomastia due to their lesser conversion rate by aromatase compared to estradiol and estrone.

B. Progesterone: Progesterone is a female sex hormone, but it is not directly responsible for hirsuitism and gynaecomastia as it is not converted into estrogens by aromatase enzyme.

C. Aromatase: Aromatase is the enzyme responsible for the conversion of androgens into estrogens, but it is not the drug causing hirsuitism and gynaecomastia. Aromatase inhibitors are used to treat conditions like breast cancer, not to cause hirsuitism and gynaecomastia.

D. Estrogen receptor blockers: These drugs prevent estrogen action on target tissues and are used to treat conditions like breast cancer, not to cause hirsuitism and gynaecomastia.

**Clinical Pearl:** Clinical cases reporting hirsuitism and gynaecomastia induced by anabolic steroids highlight the importance of understanding the pharmacology of these drugs and their adverse effects.

**Correct Answer:** D. Estrogen receptor blockers

**Explanation:** Estrogen receptor blockers work by inhibiting the action of estrogens on target tissues, preventing estrogen-induced effects. However, these drugs are used to treat conditions like breast cancer, not to cause hirsuitism and gynaecomastia. Anabolic steroids, on the other hand, promote the conversion of androgens into estrogens via the aromatase enzyme, leading to the clinical manifestations of hirsuitism and gynaecomastia.