Medical Management of Benign Prostatic Hyperplasia
Alpha-blockers are the first-line pharmacological treatment for BPH, providing rapid symptom relief with a 4-6 point improvement in AUA Symptom Index that patients perceive as meaningful. 1, 2
Initial Treatment Algorithm
Start with an alpha-blocker as initial therapy unless the patient has erectile dysfunction, in which case a PDE5 inhibitor can be initiated first. 1
Alpha-Blocker Selection
All four alpha-blockers demonstrate similar clinical effectiveness: 1, 2
- Tamsulosin (0.4-0.8 mg daily)
- Alfuzosin
- Doxazosin (titrate to 8 mg)
- Terazosin (titrate to 10 mg)
Key differences in side effect profiles guide selection: 1, 2, 3
- Tamsulosin has lower risk of orthostatic hypotension but higher probability of ejaculatory dysfunction compared to other alpha-blockers 1, 2
- Doxazosin and terazosin require dose titration to minimize first-dose hypotensive effects, while tamsulosin and alfuzosin can be initiated without titration 2
- In patients with hypertension and cardiac risk factors, doxazosin monotherapy was associated with higher incidence of congestive heart failure than other antihypertensive agents, so alpha-blockers should not be assumed to constitute optimal management of concomitant hypertension 1, 2
Common side effects across all alpha-blockers include: orthostatic hypotension, dizziness, tiredness (asthenia), ejaculatory problems, and nasal congestion. 1, 2, 3
When to Add or Switch to 5-Alpha Reductase Inhibitors
Add a 5-ARI if prostate volume >30cc 1
5-alpha reductase inhibitors (finasteride 5 mg daily or dutasteride) are appropriate only for patients with demonstrable prostatic enlargement. 1, 2, 4
Critical Prescribing Rules:
- Do NOT use 5-ARIs in patients without enlarged prostates—they are completely ineffective in this population 1, 2
- Finasteride is less effective than alpha-blockers in improving LUTS, producing only a 3-point improvement in AUA Symptom Index compared to 4-6 points with alpha-blockers 1, 2
- Requires 6 months to assess effectiveness and at least 12 months for maximum benefit 5
- Finasteride is ineffective in patients with prostate volume <40 mL 5
Indications for 5-ARI Therapy:
- Monotherapy: Symptomatic BPH with enlarged prostate to improve symptoms, reduce risk of acute urinary retention, and reduce need for surgery 4
- Combination therapy with doxazosin: To reduce risk of symptomatic progression (≥4 point increase in AUA score) 4
- Prevention of progression: Can be offered to patients with prostatic enlargement but without significant bother, though sexual dysfunction side effects and need for long-term therapy must be discussed 1
Side Effects:
Sexually related adverse events are primary concerns: decreased libido, ejaculatory dysfunction, and erectile dysfunction—all reversible upon discontinuation. 1, 4
Important safety consideration: The PCPT trial showed higher incidence of Gleason score 8-10 prostate cancer (1.8% vs 1.1% placebo), though finasteride is not approved for prostate cancer prevention. 4
PDE5 Inhibitors for BPH
Tadalafil 5 mg once daily is FDA-approved for BPH treatment and can be used for: 6
- BPH alone
- Combined erectile dysfunction and BPH
- Combination with finasteride for up to 26 weeks when initiating BPH therapy 6
Tadalafil should NOT be combined with alpha-blockers for BPH treatment. 6
Follow-Up and Treatment Adjustment
Reassess patients 4-12 weeks after initiating treatment (unless adverse events require earlier consultation) using IPSS, and consider post-void residual and uroflowmetry. 1
If lack of response or incomplete response to alpha-blocker: 1
- Consider adding 5-ARI if prostate >30cc
- Switch medication class
- Refer for procedural/surgical options
Special Clinical Scenarios
Acute Urinary Retention:
Initial treatment is catheterization followed by alpha-blocker administration prior to attempting catheter removal. 2
- Alpha-blockers significantly improve trial without catheter success rates (alfuzosin: 60% vs 39% placebo; tamsulosin: 47% vs 29% placebo) 2
- If catheter removal fails after alpha-blocker treatment, surgery is recommended 2
Absolute Indications for Surgery:
Surgery is recommended for patients with: 2
- Refractory urinary retention after failed catheter removal attempt
- Renal insufficiency due to BPH
- Recurrent UTIs refractory to therapy
- Recurrent gross hematuria refractory to therapy
- Bladder stones clearly due to BPH
Critical Pitfalls to Avoid
Never prescribe 5-ARIs without confirming prostatic enlargement—they are completely ineffective without it. 1, 2
Do not assume alpha-blockers adequately manage hypertension—patients may require separate antihypertensive management. 1, 2
Warn patients on alpha-blockers about intraoperative floppy iris syndrome (IFIS) if cataract surgery is planned. 3
Avoid balloon dilation—it is not recommended due to inadequate study results and significant failure rates over time. 2