Treatment of lower urinary tract symptoms in benign prostatic hypertrophy with α-blockers

Clinical question

Are α-blockers effective in reducing lower urinary tract symptoms in benign prostatic hypertrophy (BPH)?

Bottom line

As a first-line therapy, α-blockers are effective. Compared with placebo, around 1 in 10 patients have improved BPH symptoms or avoid symptom progression, while about 1 in 50 patients experience hypotension or dizziness. Mainly indirect comparisons suggest doxazosin and terazosin are slightly more effective but have increased risk of adverse events.

Evidence

• In a systematic review of 26 RCTs of α-blockers versus placebo, peak urinary flow (Q_max) improved by 1.32 mL/s and International Prostate Symptom Score (IPSS) decreased by 1.92.¹

• Meta-analysis of 124 RCTs comparing doxazosin, terazosin, alfuzosin, and tamsulosin found improvement in Q_max (by 1.95, 1.21, 1.07, and 1.07 mL/s, respectively) and symptoms (changes in IPSS of −3.67, −3.37, −2.13, and −2.07, respectively).²

  • -Doxazosin performed statistically significantly better for both outcomes. There was a statistically significant increase in adverse events with doxazosin and terazosin.

• A systematic review of 23 RCTs (20 821 patients) compared α-blockers to finasteride³ and found it was inferior to doxazosin and terazosin for Q_max and IPSS at 1 year, but noninferior to tamsulosin. Finasteride and dutasteride are similarly effective.⁴

• An RCT of 3047 men compared placebo with doxazosin, finasteride, and a combination.⁵ Compared with placebo, doxazosin reduced symptom progression (number needed to treat [NNT] of 15 over 4 years) and increased hypotension (number needed to harm [NNH] of 58) and dizziness (NNH = 48).

• In 3 pooled RCTs (955 patients),⁶ more men taking alfuzosin (76%) had a 3-point improvement or greater in IPSS than men taking placebo did (62%; NNT = 7).

Context

• Guidelines recommend α-blockers as first-line therapy in men with symptomatic BPH.⁷

• Clinically meaningful improvement of IPSS is 2 to 6 points or more, depending on baseline score.⁸

• Transurethral resection of the prostate improves Q_max about 10 mL/s and decreases IPSS by 16.7.⁹

• The α-blockers are associated with increased risk of falls (NNH = 589) and fracture (NNH = 1667).¹⁰

• A 2013 systematic review comparing α-blockers to combination therapy with α-reductase inhibitors showed that combination therapy was effective for enlarged prostates and treatment for longer than 1 year.¹¹

Implementation

Observational data suggest BPH is correlated with obesity and reduced physical activity.¹² Predicting progression to urinary retention is difficult, although high prostate gland volume, elevated prostate-specific antigen level, and older age might increase risk.⁷ In higher-risk patients, it might be reasonable to add α-reductase inhibitors, as they have reduced urinary retention (NNT = 60) and surgical intervention (NNT = 32) over 4 years.⁵ Side effects including adverse sexual effects (NNH = 15) should be discussed.³