Is Tadalafil (phosphodiesterase type 5 inhibitor) used to treat benign prostatic hyperplasia (BPH) in men?

Tadalafil for Benign Prostatic Hyperplasia

Yes, tadalafil 5 mg once daily is FDA-approved and guideline-recommended for treating lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH), with or without concurrent erectile dysfunction. 1, 2

Guideline Recommendations and Evidence Strength

The 2021 American Urological Association (AUA) guidelines provide a Moderate Recommendation (Evidence Level Grade B) that tadalafil 5 mg daily should be discussed as a treatment option for patients with LUTS/BPH, regardless of whether erectile dysfunction is present. 1

• The 2023 European Association of Urology guidelines similarly support tadalafil 5 mg once daily for improving LUTS based on systematic reviews and meta-analyses 3
• Tadalafil is particularly appropriate for men who desire treatment of both BPH/LUTS and erectile dysfunction simultaneously, as it addresses both conditions with a single medication 3, 4

Mechanism of Action

Tadalafil works through phosphodiesterase type 5 (PDE5) inhibition in the lower urinary tract 5, 6:

• Relaxes smooth muscle in the prostate, bladder neck, and supporting vasculature 5, 6
• Increases blood perfusion to the lower urinary tract 5
• Modulates bladder afferent nerve activity 5
• Potentially decreases smooth muscle cell proliferation in the prostate 5

Expected Clinical Efficacy

The symptom improvement with tadalafil is modest but clinically meaningful 1:

• Mean IPSS reduction of approximately -1.74 points compared to placebo (tadalafil: -5.4 points vs placebo: -3.6 points) 1
• Treatment responders (≥3 point IPSS improvement) show relative effects of 1.13 to 1.80 compared to placebo 1
• Improvements occur in both storage and voiding subscores 5, 7
• Quality of life indices improve significantly 7, 8

Important caveat: Tadalafil does NOT significantly improve maximum urinary flow rate or post-void residual volume in most studies, unlike alpha-blockers. 4

Dosing Specifications

The only recommended dose for BPH is tadalafil 5 mg once daily—higher doses provide no additional benefit for urinary symptoms. 3, 9

• Take at approximately the same time each day 2
• Can be taken with or without food 2
• Effects on LUTS are maintained with continued treatment over 1 year 7

Critical Contraindications and Safety

Absolute contraindications include: 2

• Any form of nitrate medication (nitroglycerin, isosorbide mononitrate/dinitrate, recreational "poppers")—this combination can cause fatal hypotension 2
• Guanylate cyclase stimulators (riociguat) 2
• Known hypersensitivity to tadalafil 2

Before prescribing, assess cardiovascular fitness: 3

• Verify the patient can perform moderate physical activity (walk 1 mile in 20 minutes or climb 2 flights of stairs) 3
• Refer to cardiology if unable to perform this level of activity or if cardiovascular risk is indeterminate 3

Combination Therapy: Critical Restriction

Do NOT combine tadalafil 5 mg with alpha-blockers (tamsulosin, alfuzosin, doxazosin, silodosin) for LUTS/BPH treatment. 1, 3

• The 2021 AUA guidelines explicitly state this combination offers no advantages in symptom improvement over either agent alone (Moderate Recommendation; Evidence Level Grade C) 1
• Combination therapy significantly increases adverse effects, particularly hypotension 3
• This is one of the most important clinical pitfalls to avoid 3

Optimal Patient Selection

Tadalafil is most appropriate for: 1, 3

• Men with both BPH/LUTS and erectile dysfunction who want to treat both conditions simultaneously 3, 4
• Men who prefer to avoid sexual side effects associated with alpha-blockers or 5-alpha reductase inhibitors 4
• Men with mild to moderate LUTS who prioritize sexual function preservation 4

Tadalafil is less appropriate for: 4

• Men requiring significant improvement in urinary flow rates or post-void residual volume 4
• Men with severe obstructive symptoms who need more robust voiding improvement 4

Adverse Effects Profile

Common adverse events are mild to moderate and include 7, 8:

• Headache 7
• Dyspepsia 7
• Back pain 7
• Nasal congestion 7
• Myalgia 7

No clinically adverse changes in orthostatic vital signs or uroflowmetry parameters have been observed in clinical trials. 8

Duration of Action and Clinical Considerations

• After a single dose, active ingredient remains in the body for more than 2 days 2
• This extended half-life necessitates waiting 48 hours after tadalafil before administering emergency nitrates 3
• Sexual stimulation is still required for erectile function effects 2

Evidence Base

The recommendation is supported by 11 large, 12-week, double-blind, randomized, placebo-controlled studies enrolling over 3,000 men with BPH-LUTS globally, including four Asian studies 5:

• Long-term safety and efficacy demonstrated in 42-week and 52-week studies 5
• Consistent improvements across diverse populations including Asian men 5
• Well-tolerated with favorable safety profile maintained over 1 year 7