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Can I take 50 and Flecainide together?

Drug interaction guide

Taking 5-HTP with flecainide can potentially lead to an irregular or dangerous heart rhythm. Both substances can affect how your heart beats, and combining them may increase the risk of heart rhythm disturbances.

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Why this happens

Flecainide is a powerful medicine used to control heart rhythm. 5-HTP increases serotonin levels in the body. High levels of serotonin can sometimes affect the electrical signals in the heart. When taken together, they may interfere with the heart's electrical stability, potentially leading to a serious condition called an arrhythmia.

You should not take 5-HTP while taking flecainide unless specifically instructed to do so by your cardiologist or GP. If you are already taking both, do not stop suddenly, but contact your doctor immediately to discuss your treatment. Seek urgent medical help if you experience palpitations, dizziness, fainting, or shortness of breath.

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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.

  • 14 Mar 2026 | Originally published
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