Can Xatral XL (alfuzosin) and tadalafil 10mg be combined for patients with benign prostatic hyperplasia (BPH) and erectile dysfunction (ED)?

Can Xatral XL (Alfuzosin) and Tadalafil 10mg Be Combined?

No, the combination of alfuzosin (Xatral XL) and tadalafil should not be routinely used for treating BPH, as the AUA guidelines explicitly state that combining tadalafil with alpha-blockers offers no advantages in symptom improvement over either agent alone and increases the risk of symptomatic hypotension. 1

Guideline-Based Recommendation

The 2021 American Urological Association guidelines provide a Moderate Recommendation (Evidence Level: Grade C) that clinicians should not offer the combination of low-dose daily 5mg tadalafil with alpha-blockers for the treatment of LUTS/BPH. 1

Key Reasons Against Combination:

• No added benefit: The combination does not provide superior symptom improvement compared to either medication alone 1
• Increased side effects: Both drugs are vasodilators, creating additive blood pressure-lowering effects that can lead to symptomatic hypotension (dizziness, fainting) 2
• Higher adverse event risk: The combination exposes patients to unnecessary side effects without therapeutic advantage 1

FDA Drug Label Warnings

The FDA label for tadalafil specifically addresses this combination and provides critical safety information:

For BPH Treatment:

• "The efficacy of the coadministration of an alpha-blocker and tadalafil for the treatment of BPH has not been adequately studied, and due to the potential vasodilatory effects of combined use resulting in blood pressure lowering, the combination of tadalafil and alpha-blockers is not recommended for the treatment of BPH." 2
• Patients on alpha-blocker therapy for BPH should discontinue their alpha-blocker at least one day prior to starting tadalafil for once daily use for the treatment of BPH 2

Hemodynamic Concerns:

• When vasodilators are used in combination, an additive effect on blood pressure may be anticipated, which can lead to symptomatic hypotension (e.g., fainting) 2
• The FDA warns that if tadalafil is taken with certain alpha-blockers like alfuzosin, blood pressure could suddenly drop, causing dizziness or fainting 2

Clinical Decision Algorithm

If Patient Has BPH Alone:

1. Start with alfuzosin 10mg once daily as first-line therapy 3
2. If inadequate response after 4-6 weeks, consider adding a 5-alpha-reductase inhibitor (finasteride or dutasteride) if prostate volume >30cc 4, 3
3. Do NOT add tadalafil to alfuzosin for BPH treatment 1, 2

If Patient Has Both BPH and ED:

1. Choose ONE medication, not both:
   • Option A: Continue alfuzosin for BPH, use tadalafil 10mg as-needed for ED (not daily dosing) with at least 24-hour separation from alfuzosin dose 2
   • Option B: Discontinue alfuzosin and switch to tadalafil 5mg once daily, which treats both BPH and ED 1, 2
2. Option B is preferred as it addresses both conditions with a single medication and avoids drug interaction risks 2

Evidence from Research Studies

While some research studies suggest potential benefits of combining alfuzosin and tadalafil, these findings contradict the guideline recommendations:

• A 2006 hemodynamic study showed no clinically significant blood pressure interactions between tadalafil 20mg and alfuzosin 10mg in healthy middle-aged men 5
• A 2014 randomized controlled trial found combination therapy provided greater symptomatic improvement than monotherapy in LUTS/BPH patients 6
• A 2008 in vitro study demonstrated additive relaxant effects on human corpus cavernosum 7

However, these research findings are superseded by the authoritative AUA guidelines and FDA labeling, which prioritize patient safety and real-world clinical outcomes over isolated research results. 1, 2

Critical Safety Considerations

Cardiovascular Risk:

• Both medications cause vasodilation and blood pressure reduction 2
• Patients with cardiovascular disease, those taking antihypertensives, or with intravascular volume depletion are at highest risk 2
• Symptomatic hypotension can occur, particularly with position changes 2

Common Pitfalls to Avoid:

• Do not assume that combining medications will provide additive benefits for BPH—the evidence shows otherwise 1
• Do not prescribe this combination based solely on individual research studies when guidelines explicitly recommend against it 1
• Do not forget to discontinue the alpha-blocker at least one day before starting daily tadalafil if switching therapies 2

Alternative Approach for Dual Indication

If the patient requires treatment for both BPH and ED, the evidence-based approach is:

• Discontinue alfuzosin 2
• Start tadalafil 5mg once daily, which is FDA-approved for treating both ED and BPH simultaneously 2
• This provides the benefit of treating both conditions with a single medication while avoiding drug interactions 2, 8
• Tadalafil 5mg daily showed significant improvements in both IPSS scores and erectile function in phase III trials 8