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Can I take Fluanxol and Sedoxil together?

Drug interaction guide

Taking these two medicines together can make you feel very sleepy, dizzy, and unsteady on your feet. It can also slow down your breathing and make it harder to concentrate or perform daily tasks.

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Why this happens

Both medicines work by slowing down the central nervous system (the brain and nerves). Fluanxol is an antipsychotic and Sedoxil (mexazolam) is a benzodiazepine. When used together, their calming effects add up, leading to excessive sedation.

You should only take these together if specifically prescribed by your doctor. Avoid driving, using tools, or operating machinery until you know how this combination affects you. Do not drink alcohol while taking these medicines, as it will make the sleepiness much worse. If you feel extremely drowsy or have trouble breathing, seek medical help immediately.

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Parkinson's disease

Fluanxol can significantly worsen the symptoms of Parkinson's disease and should generally be avoided.

Heart rhythm disorders (Long QT syndrome)

Fluanxol can affect your heart rhythm. You must tell your doctor if you have a history of heart rhythm problems or are taking other medicines that affect the heart.

Pregnancy

Avoid using Sedoxil during pregnancy, especially in the first and third trimesters, as it can cause harm to the developing baby and lead to withdrawal symptoms or breathing issues in the newborn.

Myasthenia gravis or severe breathing difficulties

Sedoxil can cause muscle relaxation and suppress breathing; it must not be used if you have myasthenia gravis or severe respiratory failure.

Alcohol

It is best to avoid or strictly limit alcohol while taking these medicines. Both Fluanxol and Sedoxil cause drowsiness and affect your coordination; alcohol significantly increases these effects, making you more likely to have an accident or fall. Combining alcohol with these medicines can also lead to dangerous levels of sedation and breathing difficulties.

Caffeine (Coffee, Tea, Energy Drinks)

Limit your intake of caffeine. Caffeine is a stimulant that can counteract the calming effects of Fluanxol and Sedoxil, potentially making your symptoms of anxiety or agitation worse. High amounts of caffeine can also increase the risk of restlessness and sleep disturbances.

Grapefruit and Grapefruit Juice

Avoid grapefruit and grapefruit juice. Grapefruit can interfere with the enzymes that break down Sedoxil in your body, leading to higher levels of the medicine in your bloodstream. This increases the risk of side effects such as extreme sleepiness, confusion, and dizziness.

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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.

  • 25 Jan 2026 | Originally published
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