Can I take Fluanxol and Venlafaxine together?
Drug interaction guide
Originally published 25 Jan 2026
Meets Patient’s editorial guidelines
- DownloadDownload
- Share
- Language
- Discussion
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.
In this article:
Continue reading below
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.
Continue reading below
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.
Patient picks for Drug interactions

Treatment and medication
Can I take Amoxicillin and Sertraline together?
There is no known direct interaction between amoxicillin and sertraline. It is generally considered safe to take these two medications together.

Treatment and medication
Can I take Amlodipine and Rybelsus together?
Taking Rybelsus (semaglutide) alongside amlodipine may occasionally lead to a further drop in blood pressure. While Rybelsus is primarily for blood sugar, it can sometimes cause a slight reduction in blood pressure or a small increase in heart rate. When combined with a blood pressure medicine like amlodipine, you might feel slightly more dizzy or lightheaded, especially when standing up quickly.
Continue reading below
Article history
The information on this page is written and peer reviewed by qualified clinicians.
25 Jan 2026 | Originally published

Ask, share, connect.
Browse discussions, ask questions, and share experiences across hundreds of health topics.

Feeling unwell?
Assess your symptoms online for free
Sign up to the Patient newsletter
Your weekly dose of clear, trustworthy health advice - written to help you feel informed, confident and in control.
By subscribing you accept our Privacy Policy. You can unsubscribe at any time. We never sell your data.