Can I take Amlodipine and Quetiapine together?

Why this happens

Both amlodipine and quetiapine have the side effect of lowering blood pressure. Amlodipine is designed to do this, but quetiapine can also cause 'orthostatic hypotension' (a drop in blood pressure when standing). When used together, these effects add up. Additionally, quetiapine can occasionally affect the electrical activity of the heart (QT prolongation), and while amlodipine doesn't usually cause this, the combination requires caution.

You can take these medicines together, but you should be careful. To prevent dizziness, try to stand up slowly. If you feel very dizzy, faint, or notice a fast or pounding heartbeat, contact your doctor. Your doctor may want to monitor your blood pressure more closely when you first start this combination or if your dose is changed.

Dementia in elderly patients

There is an increased risk of stroke and death when quetiapine used to treat dementia-related psychosis in elderly patients.

Suicidal thoughts and self-harm

Quetiapine can increase the risk of suicidal thoughts or self-harm, particularly in young adults (under 25). You must tell someone you trust or seek medical help immediately if your mood changes or you have thoughts of hurting yourself.

Heart disease (specifically heart rhythm disorders)

Quetiapine can affect your heart rhythm (QT prolongation). This risk is higher if you already have heart disease or take other medicines that affect the heart. Seek immediate medical help if you experience palpitations, fainting, or a racing heartbeat.

Drowsiness and impaired coordination

Quetiapine causes significant drowsiness and can affect your balance. Do not drive or operate machinery until you know how it affects you, and be careful to avoid falls, especially when getting up from a sitting or lying position.

Diabetes and blood sugar control

Quetiapine can cause a significant increase in blood sugar levels, even if you are not diabetic. If you have diabetes, you must monitor your blood sugar more closely as your medication dose may need adjusting.

Severe liver disease

Amlodipine is broken down very slowly by the liver; if you have liver problems, the dose must be adjusted carefully to avoid toxic build-up.

Severe heart disease (Aortic Stenosis)

Amlodipine should be used with extreme caution if you have narrowing of the aortic heart valve (aortic stenosis), as it can cause a dangerous drop in blood pressure and reduce blood flow to the heart.

Alcohol

It is best to avoid or strictly limit alcohol while taking these medicines. Alcohol can increase the blood-pressure lowering effect of amlodipine, making you feel dizzy or light-headed. When combined with quetiapine, alcohol can significantly increase drowsiness and impair your coordination and judgement.

Grapefruit juice

You should avoid drinking large amounts of grapefruit juice. Grapefruit can increase the concentration of both amlodipine and quetiapine in your blood, which increases the risk of side effects.

Caffeine (Coffee, Tea, Energy Drinks)

Caffeine can interfere with how quetiapine works. It may reduce the effectiveness of the medicine or worsen certain side effects like restlessness. If you consume a lot of caffeine, talk to your doctor before making any sudden changes to your intake, as this can also affect your medicine levels.

High-fat meals

If you are taking the extended-release (XL) version of quetiapine, you should avoid taking it with a very heavy or high-fat meal, as this can cause the medicine to be absorbed too quickly into your system. It is usually recommended to take it without food or with a light snack.

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.