Can I take Fluanxol and Venlafaxine together?
Drug interaction guide
Originally published 25 Jan 2026
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Taking fluanxol (flupentixol) and venlafaxine together can increase the risk of a rare but serious heart rhythm problem. It may also increase the risk of 'serotonin syndrome' (too much serotonin in the brain) and make you feel more drowsy or dizzy than usual.
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Why this happens
Both medications can affect the electrical activity of the heart (prolonging the QT interval). Additionally, both drugs influence brain chemicals like serotonin and dopamine, which can lead to additive side effects on the nervous system.
What you should do
Back to contentsYou must speak to your doctor before taking these together. They may want to perform a heart trace (ECG) or blood tests to ensure it is safe for you. Seek immediate medical help if you feel a racing heartbeat, severe dizziness, fainting, or experience muscle twitching and high fever.
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Using other medicines
Back to contentsTaking 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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