From the Research
Hydroxyzine is not absolutely contraindicated with tadalafil, but caution is advised when using these medications together. The primary concern with combining hydroxyzine and tadalafil is the potential for additive effects on QT interval prolongation, which could increase the risk of dangerous heart rhythm disturbances, particularly in patients with pre-existing cardiac conditions or other risk factors 1. Additionally, both medications can cause hypotension, and the combination might enhance this effect, leading to symptoms like dizziness or fainting.
Key Considerations
- Patients taking both medications should be monitored for these potential side effects, especially when starting treatment or adjusting dosages.
- Those with existing heart conditions, electrolyte abnormalities, or who are taking other medications that affect heart rhythm should exercise particular caution.
- If both medications are deemed necessary, starting with lower doses and gradually increasing as tolerated under medical supervision is advisable.
- Always inform your healthcare provider about all medications you are taking to avoid potential drug interactions.
Evidence Summary
The provided evidence does not directly address the interaction between hydroxyzine and tadalafil. However, studies on tadalafil's interactions with other medications suggest that it is generally safe when used with most antihypertensive agents, but co-administration with nitrates or α-blockers can cause severe hypotension and syncope 2, 3. The most recent and relevant study on drug interactions with phosphodiesterase-5 inhibitors, including tadalafil, highlights the importance of considering potential interactions with other medications, especially those that affect the cytochrome P450 enzyme system 1.
Clinical Implications
In clinical practice, the decision to use hydroxyzine and tadalafil together should be made on a case-by-case basis, taking into account the patient's individual risk factors and medical history. Close monitoring and careful dose adjustment are crucial to minimize the risk of adverse effects. Given the potential for QT interval prolongation and hypotension, patients should be advised to report any symptoms of dizziness, fainting, or palpitations promptly. Regular electrocardiogram monitoring may also be considered in high-risk patients.