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Can I take 150 and Seroquel together?

Drug interaction guide

Taking venlafaxine (Efexor) and quetiapine (Seroquel) together can increase the risk of a rare but serious heart rhythm problem. It may also increase the risk of 'serotonin syndrome', a condition where levels of a brain chemical called serotonin become too high. Additionally, both medications can cause drowsiness and dizziness, which will be more intense when taken together.

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Why this happens

Both drugs can affect the electrical activity of the heart (prolonging the QT interval). Combining them also increases serotonin levels in the brain. Furthermore, both drugs have sedative effects on the central nervous system.

You must speak to your doctor before taking these together. They may want to perform a heart trace (ECG) to check your heart rhythm. Seek immediate medical help if you feel a racing heartbeat, severe dizziness, or fainting. Do not drive or operate machinery if you feel drowsy. Avoid alcohol completely as it will worsen the sedation.

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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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