Can I take Per and Avastin together?
Drug interaction guide
Originally published 14 Mar 2026
Meets Patient’s editorial guidelines
- DownloadDownload
- Share
- Language
- Discussion
- Audio Version
There is no known direct drug-to-drug interaction between Avastin (bevacizumab) and 'per' (assuming this refers to Pertuzumab/Perjeta). However, both are powerful biological therapies used in cancer treatment that can affect the heart and immune system.
In this article:
Video picks for Drug interactions
Continue reading below
Why this happens
Both drugs are monoclonal antibodies. While they work on different pathways (Avastin targets blood vessel growth, while Pertuzumab targets HER2 receptors on cancer cells), using them together or in sequence can increase the overall strain on the body, particularly the heart muscle.
What you should do
Back to contentsThese medications are only ever prescribed together by a specialist oncologist. You must ensure your medical team has a full list of all your medicines. Your doctor will likely monitor your heart function (using scans like an ECHO or MUGA) and your blood counts regularly while you are on these treatments. Report any new shortness of breath or swelling in your ankles immediately.
Continue reading below
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.
Patient picks for Drug interactions

Treatment and medication
Can I take Allerwel am and Calpol together?
There are no known harmful interactions between Allerwel AM and Calpol. It is generally safe to take these two medicines together as long as you follow the recommended doses for each.

Treatment and medication
Can I take Desmopressin and Ketoconazole together?
Taking these two medicines together can significantly increase the amount of desmopressin in your blood. This can lead to your body holding onto too much water, which can cause a dangerous drop in your blood salt levels (hyponatraemia). Symptoms to watch for include severe headache, nausea, vomiting, confusion, or feeling very drowsy.
Continue reading below
Article history
The information on this page is written and peer reviewed by qualified clinicians.
14 Mar 2026 | Originally published

Ask, share, connect.
Browse discussions, ask questions, and share experiences across hundreds of health topics.

Feeling unwell?
Assess your symptoms online for free
Sign up to the Patient newsletter
Your weekly dose of clear, trustworthy health advice - written to help you feel informed, confident and in control.
By subscribing you accept our Privacy Policy. You can unsubscribe at any time. We never sell your data.