Can I take Flecainide and Mirabegron astellas together?
Drug interaction guide
Originally published 25 Jan 2026
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Taking these two medicines together can increase the level of flecainide in your blood. This may increase the risk of side effects, such as an irregular heartbeat (arrhythmia), dizziness, or blurred vision.
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Why this happens
Mirabegron can slow down the action of a specific enzyme in the liver (called CYP2D6) that is responsible for breaking down flecainide. Because the flecainide is broken down more slowly, it can build up to higher levels in your body.
What you should do
You should speak to your doctor before taking these medicines together. Your doctor may need to adjust your dose of flecainide or monitor your heart rhythm more closely using an ECG (electrocardiogram). If you experience any new palpitations, fainting, or shortness of breath, seek medical advice immediately.
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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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