All of the following drugs can cause gynaecomastia except:-
**Question:** All of the following drugs can cause gynaecomastia except:-
A. Tamoxifen
B. Testosterone
C. Amiodarone
D. Spironolactone
**Core Concept:**
Gynaecomastia is the medical term for the enlargement of the breast tissue in males due to hormonal imbalances or other causes. It is usually caused by the excess production of estrogen or the deficiency of androgens. Drugs can interfere with hormonal balance and lead to gynaecomastia.
**Why the Correct Answer is Right:**
The correct answer, D - Spironolactone, is a diuretic and potassium-sparing agent that is used to treat high blood pressure and edema. Spironolactone is a selective aldosterone antagonist, which means it blocks the action of aldosterone (a hormone responsible for maintaining electrolyte balance in the body) at the cellular level. As a result, it does not lead to hormonal imbalance that can cause gynaecomastia.
**Why Each Wrong Option is Incorrect:**
A. Tamoxifen (Option A) is a selective estrogen receptor modulator (SERM) that is primarily used to treat breast cancer by blocking estrogen-induced cellular proliferation. It can cause gynaecomastia due to its estrogenic effects.
B. Testosterone (Option B) is the primary male sex hormone responsible for masculinization and is crucial for male sexual development and well-being. Deficiency of testosterone can lead to various issues, including gynecomastia. Testosterone does not cause gynecomastia but helps maintain a balance between estrogen and androgen levels in males.
C. Amiodarone (Option C) is a class III antiarrhythmic drug used to regulate heart rate and rhythm. It is a phenothiazine derivative and contains iodine, which can cause hypothyroidism and hormonal imbalance, leading to gynaecomastia.
**Clinical Pearl:**
In clinical practice, gynaecomastia should be considered in men who develop breast enlargement during chemotherapy or when taking drugs like antiarrhythmics or estrogenic medications. Evaluating the patient's medication use history is essential in identifying the cause of gynaecomastia.