Can I take Fluanxol and Prozac together?
Drug interaction guide
Originally published 25 Jan 2026
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Taking these two medicines together can increase the risk of a serious heart rhythm problem called QT prolongation. It can also lead to an excessive buildup of fluanxol in your body, which may cause severe side effects like uncontrollable muscle movements, stiffness, or extreme restlessness.
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Why this happens
Prozac (fluoxetine) blocks the liver enzymes (specifically CYP2D6) that your body uses to break down Fluanxol (flupentixol). This causes the levels of Fluanxol in your blood to rise significantly. Additionally, both drugs have a side effect that can affect the electrical activity of your heart.
What you should do
You must speak to your doctor before taking these together. They may need to lower your dose of Fluanxol or perform an ECG (heart trace) to check your heart rhythm. Seek immediate medical help if you feel dizzy, faint, or notice a fast or pounding heartbeat.
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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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