Can I take Amitriptyline and Oxycodone together?

Why this happens

Both drugs slow down the central nervous system (brain and spinal cord). Amitriptyline also increases serotonin levels, which can be further affected by oxycodone, leading to a dangerous build-up. Additionally, amitriptyline can slow down the body's ability to process oxycodone, making its effects stronger and longer-lasting.

What you should do

You must speak to your doctor before taking these medicines together. If your doctor prescribes both, they will likely start you on the lowest possible doses. Seek immediate medical help if you feel unusually sleepy, have trouble breathing, or feel very confused.

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.

Respiratory Depression / Breathing Problems

Both medicines can slow your breathing. Taking them together significantly increases the risk of dangerous, shallow breathing or stopping breathing altogether. Seek emergency help if you feel extremely drowsy or have difficulty breathing.

Opioid Addiction and Dependence

Oxycodone is an opioid that carries a high risk of addiction and physical dependence, even at prescribed doses. Long-term use can lead to withdrawal symptoms if stopped suddenly.

Heart Rhythm Disorders

Amitriptyline can affect your heart rhythm (QT prolongation). It must be used with extreme caution if you have an existing heart condition or a history of heart attacks.

Food and drink warnings

Alcohol

You must avoid or strictly limit alcohol while taking these medicines. Both amitriptyline and Oxycodone cause drowsiness and slow your breathing; alcohol significantly increases these effects, which can lead to dangerous levels of sedation, coordination loss, and respiratory depression.

Grapefruit juice

Avoid drinking grapefruit juice or eating grapefruit. It can increase the amount of oxycodone in your blood to potentially toxic levels, increasing the risk of serious side effects like extreme sleepiness or breathing difficulties.

Caffeine (Coffee, tea, energy drinks)

Amitriptyline can sometimes cause a fast or irregular heartbeat. High intake of caffeine may worsen these heart-related side effects or increase feelings of restlessness and anxiety.

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.