Can I take Flecainide and Tamsulosin together?
Drug interaction guide
Originally published 25 Jan 2026
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Taking flecainide and tamsulosin together may increase the levels of tamsulosin in your blood. This can make you more likely to experience side effects such as dizziness, lightheadedness, or a sudden drop in blood pressure when you stand up (fainting).
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Why this happens
Both drugs are processed by the same enzyme in the liver (CYP2D6). Flecainide can slow down this enzyme, which prevents tamsulosin from being broken down as quickly as usual, leading to higher levels of the drug in your system.
What you should do
You can take these medicines together, but you should be cautious. Monitor your blood pressure and watch for signs of dizziness, especially when moving from a sitting or lying position to standing. If you feel very dizzy or faint, contact your doctor, as they may need to adjust your tamsulosin dose.
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Using other medicines
Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.
Disclaimer
This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.
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Article history
The information on this page is written and peer reviewed by qualified clinicians.
25 Jan 2026 | Originally published

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