Regarding the pathophysiology and medical management of benign prostatic hyperplasia (BPH), all of the following statements are correct EXCEPT:

Explanation

## Pathophysiology of BPH **Key Point:** BPH results from age-dependent proliferation of epithelial and stromal cells in the transition zone of the prostate, mediated by androgens (DHT) and growth factors. ## Medical Management Modalities ### Alpha-1 Adrenergic Antagonists **High-Yield:** Alpha-blockers (tamsulosin, alfuzosin, doxazosin) relax smooth muscle in the prostatic capsule and bladder neck via α1A-receptor blockade. - Onset of action: **3–7 days** (some symptom relief within days) - Do NOT reduce prostate volume - Effective for LUTS regardless of prostate size - Side effects: orthostatic hypotension, retrograde ejaculation, dizziness ### 5-Alpha Reductase Inhibitors **Key Point:** Finasteride (Type II inhibitor) and dutasteride (Type I + II inhibitor) block DHT synthesis. - Onset: **slow** — 6–12 months for maximal effect - Reduce prostate volume by **25–30%** (or up to 50% with dutasteride in large glands) - Indicated when prostate >40 g or PSA >1.5 ng/mL - Side effects: erectile dysfunction, decreased libido, gynaecomastia (rare) ### Combination Therapy **Clinical Pearl:** MTOPS trial and subsequent evidence show combination therapy (alpha-blocker + 5-alpha reductase inhibitor) is superior to monotherapy in men with: - Large prostate volume (>40 g) - Moderate-to-severe LUTS - High risk of progression ### Phosphodiesterase-5 Inhibitors **High-Yield:** Tadalafil (5 mg daily) is **approved and recommended** for BPH-LUTS, especially in men with concurrent erectile dysfunction. - Mechanism: smooth muscle relaxation in prostate and bladder - Safe in combination with alpha-blockers (use caution with doxazosin due to hypotension) - **NOT contraindicated** — actually beneficial in dual pathology - Improves LUTS and erectile function simultaneously ## Why Option 3 is Incorrect **Warning:** The statement claims PDE5 inhibitors are **contraindicated in all men with BPH and ED** — this is **FALSE**. Tadalafil is explicitly indicated and safe in this population, often preferred because it addresses both conditions. There is no absolute contraindication; the only caution is additive hypotension when combined with certain alpha-blockers (particularly doxazosin). ## Summary Table: Medical Agents for BPH | Agent Class | Onset | Volume Reduction | LUTS Relief | Indication | | --- | --- | --- | --- | --- | | Alpha-blockers | Days–weeks | No | Yes | All LUTS | | 5-ARI | 6–12 months | Yes (25–50%) | Modest | Large prostate, high PSA | | PDE5i (tadalafil) | Weeks | No | Yes | BPH + ED | | Combination (α + 5-ARI) | Variable | Yes | Yes | Large prostate + severe LUTS |