Dutasteride for Benign Prostatic Hyperplasia
Dutasteride works for benign prostatic hyperplasia: high-quality trials show it shrinks the prostate, eases urinary symptoms, and lowers the risk of acute urinary retention and surgery. It is an approved prescription drug, but its grade is tempered by industry-funded pivotal trials and real safety signals, including sexual side effects and a high-grade prostate cancer signal.
Why this grade7-layer evidence engine
The efficacy signal is robust and consistent. A high-quality meta-analysis of placebo-controlled trials (PMID 24500194) found dutasteride lowered symptom scores (IPSS -1.78), raised peak urine flow (+1.27 mL/s), and shrank prostate volume (-17.40 cm3). The 4-year CombAT trial (PMID 19825505, n=4844) showed dutasteride plus tamsulosin cut acute urinary retention and BPH surgery more than tamsulosin alone, and the REDUCE trial (PMID 20357281, n=6729) confirmed a large reduction in urinary retention. FDA, the UK NHS/BNF, and Mayo, Cleveland, and Harvard clinics all treat it as standard, approved BPH therapy.
Why only B rather than top-tier: the two pivotal long-term RCTs (CombAT, REDUCE) were industry-funded by the manufacturer, triggering an industry-funding flag, and genuine counter-evidence exists. In REDUCE (PMID 20357281), although overall prostate cancer detection fell 22.8%, high-grade Gleason 8-10 tumors were more frequent in years 3-4 (12 vs 1, p=0.003), prompting an FDA class warning, and cardiac failure was higher (0.7% vs 0.4%).
Practical caveats matter for this category. The placebo-controlled meta-analysis reported more adverse events overall (RR 1.35), and sexual side effects (reduced libido, erectile and ejaculation problems) are well documented. Benefits build slowly, with meaningful prostate shrinkage taking roughly 6-12 months, and the drug lowers PSA by about half, which must be accounted for in cancer screening. Head-to-head with finasteride (PMID 35402192, n=2116), dutasteride was only marginally better on urine flow (MD 0.32 mL/s) and similar on most other outcomes.
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditable▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.694
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 無高階證據可裁決
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 1 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status