Can I take Lansoprazole and Quetiapine together?

Why this happens

Lansoprazole reduces stomach acid, which can change how quetiapine dissolves and is absorbed. By making the stomach less acidic, lansoprazole may slightly lower the amount of quetiapine that gets into your bloodstream. Additionally, both medications have the potential to affect the electrical activity of the heart (prolonging the QT interval), and using them together may increase this risk.

What you should do

You should speak to your doctor before taking these together. They may want to perform a simple heart trace (ECG) to check your heart rhythm or monitor your symptoms more closely. Seek immediate medical help if you feel dizzy, faint, or notice a fluttering or pounding heartbeat.

Important precautions

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 rhythm disorders (Long QT syndrome)

Quetiapine can affect your heart rhythm. You must tell your doctor if you have a history of heart disease, slow heart rate, or if you are taking other medicines that can cause 'QT prolongation'.

Severe diarrhoea

Lansoprazole can increase your risk of serious bowel infections. If you develop severe or persistent watery diarrhoea, or a fever, contact your doctor immediately and do not take anti-diarrhoeal medicine.

Lupus (SLE) or skin reactions

Contact your doctor if you develop a skin rash, especially in areas exposed to the sun, as lansoprazole can cause a rare but serious autoimmune skin reaction.

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.

Dementia-related psychosis

Quetiapine must not be used to treat elderly patients with dementia-related psychosis, as it significantly increases the risk of stroke and death in this group.

Diabetes and high blood sugar

Quetiapine can cause a significant increase in blood sugar levels, which can lead to or worsen diabetes. You should monitor for symptoms like extreme thirst or frequent urination.

Food and drink warnings

Alcohol

It is best to avoid or strictly limit alcohol while taking lansoprazole. Alcohol increases the amount of acid your stomach produces, which can make your symptoms worse and counteract the effects of the medicine.

It is best to avoid or strictly limit alcohol while taking quetiapine. Combining the two can significantly increase drowsiness and dizziness, making you more likely to fall or have an accident. It can also impair your coordination and judgement.

Food (Timing)

Lansoprazole works best if you take it at least 30 minutes before food. Taking it with or after food can make it less effective at reducing stomach acid.

Grapefruit juice

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

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.

Lansoprazole is often prescribed for acid reflux. Caffeine can trigger or worsen reflux symptoms by relaxing the muscle at the base of the food pipe, which may make your medicine less effective at managing your symptoms.

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. This can cause the medicine to be absorbed into your system too quickly (known as 'dose dumping'), which increases the risk of side effects. It is usually best to take it without food or with a light snack.

Using other medicines

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.