Can I take Amitriptyline and Thyroxine together?
Drug interaction guide
Originally published 12 May 2026
Meets Patient’s editorial guidelines
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Taking amitriptyline and thyroxine (levothyroxine) together may increase the risk of heart-related side effects, such as a fast heartbeat or an irregular heart rhythm (palpitations). It may also increase the risk of feeling anxious or shaky.
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Why this happens
Thyroxine makes the heart more sensitive to certain chemicals in the body, such as adrenaline. Amitriptyline increases the levels of these chemicals. When used together, they can have an 'additive' effect, putting extra strain on the heart and nervous system.
What you should do
Back to contentsThis combination is commonly prescribed, but you should be monitored by your doctor. If you notice a very fast heartbeat, chest pain, or severe tremors, contact your GP. Do not stop taking either medication without medical advice.
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Using other medicines
Back to contentsTaking 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.
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Article history
The information on this page is written and peer reviewed by qualified clinicians.
12 May 2026 | Originally published

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