Can I take Letrozole and Mirtazipine together?
Drug interaction guide
Originally published 12 May 2026
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There is no known direct interaction between letrozole and mirtazapine. However, both medications can cause drowsiness or fatigue as side effects, which may be more noticeable when taken together. Additionally, mirtazapine can sometimes cause weight gain, which may be a concern for patients taking letrozole for breast cancer treatment.
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Why this happens
Letrozole is an aromatase inhibitor used to treat breast cancer, while mirtazapine is an antidepressant. They are processed by different pathways in the liver and do not interfere with how the other is absorbed or cleared from the body. Any shared side effects, like tiredness, are simply additive rather than a chemical reaction between the two drugs.
What you should do
Back to contentsYou can safely take these two medicines together. Be aware that you might feel more tired than usual, especially when first starting mirtazapine. If you experience significant mood changes or excessive weight gain, discuss this with your doctor. Always inform your oncology team about any new medications you are prescribed.
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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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