Skip to main content

Can I take Qutan and Sizodon md together?

Drug interaction guide

Taking these two medicines together can increase the risk of side effects such as extreme sleepiness, dizziness, and confusion. It may also increase the risk of 'orthostatic hypotension' (a sudden drop in blood pressure when you stand up), which can lead to fainting or falls. In some cases, it can increase the risk of heart rhythm problems or movement disorders (shaking or stiffness).

Video picks for Drug interactions

Continue reading below

Why this happens

Both Qutan (quetiapine) and Sizodon MD (risperidone) are antipsychotic medications that work on similar pathways in the brain. Because they both have sedative effects and affect blood pressure regulation, taking them together creates an 'additive effect' where the impact of both drugs is combined.

You must speak to your doctor before taking these two medicines together. They are usually not prescribed at the same time unless specifically managed by a specialist. If your doctor has prescribed both, report any unusual dizziness, fainting, or extreme drowsiness immediately. Be careful when getting out of bed or standing up quickly.

Continue reading below

Dementia-related psychosis in elderly patients

These medicines significantly increase the risk of stroke and death in elderly patients with dementia. They are not approved for treating dementia-related behavioural problems.

Neuroleptic Malignant Syndrome (NMS)

Seek emergency medical help immediately if you develop a high fever, severe muscle stiffness, confusion, or rapid heartbeat. This is a rare but life-threatening reaction.

Diabetes and high blood sugar

These medicines can cause extreme increases in blood sugar, even in people without diabetes. Monitor for excessive thirst, frequent urination, or extreme weakness, as this can lead to a life-threatening ketoacidosis.

Alcohol

You must avoid drinking alcohol while taking these medicines. Both Qutan and Sizodon MD can cause significant drowsiness and dizziness. Alcohol will greatly increase these effects, making you feel very sleepy and increasing the risk of falls or accidents.

Grapefruit juice

Avoid drinking grapefruit juice or eating grapefruit while taking Qutan. Grapefruit can increase the amount of this medicine in your blood, which makes side effects much more likely and potentially more severe.

Caffeine (Coffee, tea, cola)

Be cautious with drinks containing caffeine. Caffeine can sometimes interfere with how well Sizodon MD works or may worsen certain side effects like restlessness or tremors.

Continue reading below

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.

Continue reading below

Article history

The information on this page is written and peer reviewed by qualified clinicians.

  • 14 Mar 2026 | Originally published
flu eligibility checker

Ask, share, connect.

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

symptom checker

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.

Please enter a valid email address

By subscribing you accept our Privacy Policy. You can unsubscribe at any time. We never sell your data.