What are the recommended medications for treating Benign Prostatic Hyperplasia (BPH)?

Recommended Medications for Benign Prostatic Hyperplasia (BPH)

Alpha blockers are the first-line medication treatment for BPH, with 5-alpha reductase inhibitors (5-ARIs) recommended for men with demonstrable prostatic enlargement. 1

Alpha Blockers

Alpha blockers are the cornerstone of medical therapy for BPH due to their rapid onset of action and effectiveness in symptom relief.

• Five alpha blockers are recommended as treatment options for moderate to severe LUTS/BPH: alfuzosin, doxazosin, silodosin, tamsulosin, and terazosin 1
• All five agents have similar clinical effectiveness, producing on average a 4-7 point improvement in IPSS (International Prostate Symptom Score) compared to 2-4 points with placebo 1, 2
• The choice of alpha blocker should be based on patient age, comorbidities, and different adverse event profiles 1
• Tamsulosin is typically dosed at 0.4 mg once daily, approximately 30 minutes after the same meal each day 3
• Alpha blockers work by inhibiting alpha1-adrenergic-mediated contraction of prostatic smooth muscle, relieving bladder outlet obstruction 1

Adverse Effects of Alpha Blockers

• Tamsulosin appears to have a lower probability of orthostatic hypotension but a higher probability of ejaculatory dysfunction compared to other alpha blockers 2
• Common adverse events include dizziness, rhinitis, abnormal ejaculation, and asthenia (tiredness) 2, 4
• Patients planning cataract surgery should be informed about the risk of intraoperative floppy iris syndrome (IFIS) associated with alpha blockers 1

5-Alpha Reductase Inhibitors (5-ARIs)

5-ARIs are recommended for men with larger prostates and are effective in preventing disease progression.

• 5-ARI monotherapy (finasteride, dutasteride) should be used in patients with LUTS/BPH with prostatic enlargement as judged by:
  • Prostate volume >30cc on imaging, OR
  • PSA >1.5ng/mL, OR
  • Palpable prostate enlargement on digital rectal exam (DRE) 1
• Finasteride is indicated for:
  • Improving symptoms
  • Reducing the risk of acute urinary retention
  • Reducing the risk of surgery including TURP and prostatectomy 5
• 5-ARIs work by blocking the conversion of testosterone to dihydrotestosterone, leading to prostate volume reduction 6

Adverse Effects of 5-ARIs

• Sexual side effects are common with 5-ARIs, including:
  • Impotence (8.1% in year 1)
  • Decreased libido (6.4% in year 1)
  • Decreased volume of ejaculate (3.7% in year 1) 5
• These sexual side effects tend to decrease after the first year of treatment 5

Combination Therapy

Combination therapy may provide additional benefits for selected patients.

• 5-ARI in combination with an alpha blocker should be offered only to patients with demonstrable prostatic enlargement (prostate volume >30cc, PSA >1.5ng/mL, or palpable enlargement) 1
• Finasteride administered in combination with doxazosin is specifically indicated to reduce the risk of symptomatic progression of BPH 5
• Two large studies (MTOPS and CombAT) showed statistically significant reductions in clinical progression with combination therapy over monotherapy 1
• Anticholinergic agents, alone or in combination with an alpha blocker, may be offered to patients with moderate to severe predominant storage LUTS 1
• Beta-3-agonists in combination with an alpha blocker may be offered to patients with moderate to severe predominant storage LUTS 1
• The combination of low-dose daily 5mg tadalafil with alpha blockers is not recommended as it offers no advantages in symptom improvement over either agent alone 1, 2

Phosphodiesterase-5 Inhibitors (PDE5)

• For patients with LUTS/BPH, regardless of erectile dysfunction status, 5mg daily tadalafil should be discussed as a treatment option 1
• Tadalafil 5mg produces a modest improvement in IPSS compared to placebo, with a mean change of -1.74 points 1
• This option is most reasonable for men who also have erectile dysfunction 1

Acute Urinary Retention Management

• Physicians should prescribe an oral alpha blocker prior to a voiding trial for patients with acute urinary retention (AUR) related to BPH 1
• Patients should complete at least three days of alpha blocker therapy before attempting a trial without catheter (TWOC) 1
• Patients who successfully pass a TWOC should be informed that they remain at increased risk for recurrent urinary retention 1
• Alpha blockers like alfuzosin and tamsulosin improve TWOC success rates (60% vs 39% for placebo with alfuzosin; 47% vs 29% for placebo with tamsulosin) 1

Treatment Algorithm

1. For initial treatment of moderate to severe LUTS/BPH:

   • Start with alpha blocker monotherapy for most patients 1
   • Consider 5-ARI monotherapy if prostate is enlarged (>30cc) 1
   • Consider tadalafil 5mg daily, particularly if erectile dysfunction is present 1

2. For patients with inadequate response to alpha blocker monotherapy:

   • Add 5-ARI if prostate is enlarged (>30cc, PSA >1.5ng/mL, or palpable enlargement) 1
   • Consider adding anticholinergic agent if storage symptoms predominate 1
   • Consider adding beta-3-agonist if storage symptoms predominate 1

3. For acute urinary retention:

   • Prescribe alpha blocker (alfuzosin or tamsulosin)
   • Continue for at least 3 days before attempting TWOC 1

Common Pitfalls and Caveats

• Failing to assess prostate size before initiating 5-ARI therapy (5-ARIs are only effective for enlarged prostates) 1
• Not informing patients about sexual side effects of 5-ARIs 5
• Not checking post-void residual (PVR) before and during treatment with anticholinergics 1
• Combining tadalafil with alpha blockers, which provides no additional benefit but increases side effect risk 1
• Not informing ophthalmologists about alpha blocker use before cataract surgery 1
• Not recognizing that patients who pass a TWOC after AUR remain at high risk for recurrent retention 1