From the Guidelines
The use of tadalafil and naftopidil together is not recommended due to the higher risk of side effects, as stated in the 2021 AUA guideline 1. When considering the combination of these two medications, it's crucial to weigh the potential benefits against the risks, particularly the increased risk of side effects. The guideline suggests that the combination of a phosphodiesterase inhibitor like tadalafil and an alpha-adrenergic blocker like naftopidil may not be the best approach for managing lower urinary tract symptoms attributed to benign prostatic hyperplasia.
Some key points to consider when evaluating the safety of using tadalafil and naftopidil together include:
- The potential for additive blood pressure-lowering effects, which could lead to symptomatic hypotension
- The importance of medical supervision and careful monitoring of blood pressure if the combination is used
- The need to start with lower doses and gradually increase as tolerated to minimize the risk of side effects
It's also important to note that the 2021 AUA guideline 1 recommends against the combination of tadalafil and naftopidil, suggesting that the risks may outweigh the benefits. Therefore, alternative treatment options should be considered, and patients should be closely monitored if the combination is used.
In terms of specific guidance, the following points are relevant:
- Tadalafil should be used with caution in patients taking alpha-blockers like naftopidil
- Patients should be informed about the potential risks and benefits of the combination and monitored closely for signs of hypotension or other side effects
- The timing of medication administration and the starting dose of tadalafil may need to be adjusted to minimize the risk of interactions.
From the FDA Drug Label
Caution is advised when PDE5 inhibitors are coadministered with alpha-blockers. PDE5 inhibitors, including tadalafil, and alpha-adrenergic blocking agents are both vasodilators with blood-pressure-lowering effects. When vasodilators are used in combination, an additive effect on blood pressure may be anticipated In some patients, concomitant use of these two drug classes can lower blood pressure significantly [see Drug Interactions (7.1) and Clinical Pharmacology (12.2)], which may lead to symptomatic hypotension (e.g., fainting).
The use of tadalafil and naftopidil together is not entirely safe, as caution is advised when coadministering PDE5 inhibitors like tadalafil with alpha-blockers like naftopidil due to the potential for additive blood-pressure-lowering effects and increased risk of symptomatic hypotension. Patients should be stable on alpha-blocker therapy prior to initiating tadalafil, and the lowest recommended dose of tadalafil should be used. 2 2
From the Research
Safety of Using Tadalafil and Naftopidil Together
- The use of tadalafil, a phosphodiesterase inhibitor, and naftopidil, an alpha-adrenergic blocker, together may pose some risks, particularly related to blood pressure regulation 3, 4.
- Studies have shown that when PDE5 inhibitors like tadalafil are administered to patients taking alpha-blockers, there is a potential for orthostatic hypotension, although this interaction may be less clinically relevant in patients undergoing long-term alpha-blocker therapy 3.
- Tadalafil has been found to be safe in patients receiving concomitant antihypertensive agents, including alpha-blockers, with mild and not clinically significant reductions in blood pressure 5.
- However, precautions are necessary when using PDE5 inhibitors with alpha-blockers, as some patients may develop orthostatic hypotension 4.
Considerations for Combined Therapy
- The safety of using tadalafil and naftopidil together has not been directly studied in the provided evidence.
- However, based on the available data, it is essential to exercise caution and monitor blood pressure when combining these medications 3, 4, 5.
- Patients should be closely monitored for signs of orthostatic hypotension, and the dosage of either medication may need to be adjusted to minimize the risk of adverse interactions 3, 4.