Drug not causing gynaecomastia is ?
**Core Concept**
Gynaecomastia is a benign enlargement of breast tissue in males, often caused by an imbalance of sex hormones, specifically an excess of estrogen relative to testosterone. This condition can be triggered by various medications that alter hormone levels or affect the body's response to sex hormones.
**Why the Correct Answer is Right**
The correct answer is a medication that does not interfere with the delicate balance of sex hormones in the body. Most medications that cause gynaecomastia do so by inhibiting the enzyme 5-alpha-reductase, which converts testosterone to dihydrotestosterone (DHT), a more potent form of testosterone. Alternatively, some medications may stimulate estrogen production or block androgen receptors, leading to an imbalance of sex hormones.
**Why Each Wrong Option is Incorrect**
**Option A:** Medications that inhibit 5-alpha-reductase, such as finasteride, can cause gynaecomastia by reducing DHT levels and increasing the relative amount of testosterone, which is converted to estrogen.
**Option B:** Estrogenic medications, such as digitalis, can directly stimulate estrogen receptors, leading to an imbalance of sex hormones and gynaecomastia.
**Option C:** Anti-androgen medications, such as spironolactone, can block androgen receptors, reducing the effects of testosterone and potentially leading to gynaecomastia.
**Clinical Pearl / High-Yield Fact**
Medications that cause gynaecomastia often have a common underlying mechanism: they disrupt the balance of sex hormones in the body. Identifying these medications can be crucial for managing gynaecomastia in patients.
**Correct Answer: D.**