A drug ‘X’ primarily reduces the static component of urinary obstruction in benign hypertrophy of prostate and takes more than 3 months to exert its beneficial effect. Which of the following is ‘X’ ?
**Core Concept**
The question is testing the understanding of **benign prostatic hyperplasia (BPH)** treatment, specifically the pharmacological management of urinary obstruction. The focus is on a drug that reduces the static component of obstruction, which is related to the size of the prostate gland.
**Why the Correct Answer is Right**
The correct answer is a **5-alpha-reductase inhibitor**, which blocks the conversion of testosterone to dihydrotestosterone (DHT), a hormone that promotes prostate growth. By reducing DHT levels, these drugs decrease the size of the prostate, thus alleviating the static component of urinary obstruction. This process takes time, typically more than 3 months, to exert its beneficial effect.
**Why Each Wrong Option is Incorrect**
**Option A:** Would be incorrect because it might represent a different class of drugs, such as alpha-blockers, which primarily reduce the dynamic component of obstruction by relaxing smooth muscle in the prostate and bladder neck.
**Option B:** and **Option D:** Could represent other treatments or drugs not specifically known for reducing prostate size over months.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that **5-alpha-reductase inhibitors** are most beneficial for patients with larger prostates, as they reduce the size of the gland over time, thereby improving symptoms.
**Correct Answer:** D. Finasteride.