Can I take Amitriptyline and Quinine together?

Why this happens

Both amitriptyline and quinine can affect the electrical activity of the heart (specifically by prolonging the 'QT interval'). When used together, this effect is added together, making it more likely that the heart's rhythm will become unstable. Additionally, quinine may slow down how quickly the liver breaks down amitriptyline, leading to higher levels of the medicine in your blood.

What you should do

You should speak to your doctor before taking these two medicines together. They may want to check your heart rhythm with an ECG (heart trace) or consider an alternative treatment for leg cramps or depression. If you are already taking both and feel dizzy, faint, or notice your heart beating very fast or irregularly, seek medical help immediately.

Important precautions

Suicidal thoughts and mood changes

Amitriptyline can increase the risk of suicidal thoughts or self-harm, particularly when first starting treatment or changing doses. Seek immediate medical help if your mood changes or you feel depressed.

Heart rhythm disorders (e.g., Long QT syndrome)

Quinine can cause serious, potentially fatal heart rhythm problems. You must not take it if you have a history of heart rhythm issues or are taking other medicines that affect your heart rate.

Pregnancy

Do not take quinine if you are pregnant or planning to become pregnant, as high doses can cause birth defects or miscarriage. It should only be used in pregnancy if specifically prescribed by a specialist to treat malaria.

Glaucoma (specifically acute angle-closure)

Amitriptyline can significantly increase pressure inside the eye. If you have glaucoma, this medicine can trigger an emergency medical crisis (acute glaucoma attack).

Heart disease (recent heart attack or heart failure)

Both medicines can affect the electrical signals in your heart. Amitriptyline is particularly dangerous if taken shortly after a heart attack, as it increases the risk of sudden cardiac arrest.

Food and drink warnings

Alcohol

Drinking alcohol while taking amitriptyline can make you feel very sleepy and unsteady on your feet. It is best to avoid alcohol, especially when you first start treatment or if your dose is increased.

Grapefruit juice

Grapefruit juice can increase the amount of quinine in your blood, which may increase the risk of side effects. It is best to avoid drinking large amounts of grapefruit juice while taking this medicine.

Beverages containing quinine (e.g., Tonic Water)

Avoid consuming large amounts of tonic water or other beverages containing quinine, as this can increase the risk of side effects from your medication.

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.