The short answer
Afinitor (Everolimus) is a targeted therapy called an mTOR inhibitor. It blocks a protein called mTOR that helps cancer cells grow, divide, and form blood vessels. It is used to help treat some breast, kidney, and neuroendocrine cancers, and is usually given as tablets taken by mouth each day. Like all cancer medicines it can cause side effects; this page explains the common ones and the warning signs to report. It is educational only and not a substitute for your care team's advice.
Afinitor is the brand name; its generic name is everolimus.
It is a targeted therapy called an mTOR inhibitor — it blocks a protein called mTOR that helps cancer cells grow, divide, and form blood vessels.
It is used to help treat some breast, kidney, and neuroendocrine cancers.
It is usually given as tablets taken by mouth each day.
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The full explanation.
One drug, several cancers and a genetic condition
Afinitor is the brand name. Everolimus is the generic name. It blocks mTOR, a switch inside the cell that decides whether to grow, divide and build blood vessels. Turn the switch down and growth slows.
The approved uses are unusually mixed.
- Advanced breast cancer that is hormone receptor positive and HER2 negative, after menopause, given with exemestane, once letrozole or anastrozole has stopped working.
- Neuroendocrine tumors of the pancreas that are progressing. Also progressing, well-differentiated, non-functional neuroendocrine tumors of the gut or lung. The label states it is not for functional carcinoid tumors.
- Advanced kidney cancer, after sunitinib or sorafenib have been tried.
- Kidney angiomyolipoma in tuberous sclerosis complex, where surgery is not needed straight away.
- A brain tumor called SEGA in tuberous sclerosis complex, from age 1, when it needs treating but cannot be fully removed.
- Seizures in tuberous sclerosis complex, from age 2, as an add-on. That use is for Afinitor Disperz, a version that dissolves in water.
For breast cancer, neuroendocrine tumors and kidney cancer the dose is 10 mg once a day.
That is the amount printed on the label. Your own team writes your prescription, and they lower it when mouth ulcers, lung inflammation or other medicines make that sensible.
Mouth sores are the most common reason to change the dose
Stomatitis, meaning mouth ulcers and sore inflamed lining, occurred in 44% to 78% of people across the trials in the label. It was severe in 4% to 9%. It usually starts within the first 8 weeks.
This matters because it is the thing most likely to interrupt treatment. Ask your team on day one what mouthwash or gel they want you to use, and start it before anything hurts. Alcohol-based mouthwashes and hydrogen peroxide tend to make it worse. Tell the team as soon as eating or drinking gets difficult, because a short pause or a lower dose often fixes it.
Lung inflammation and infection risk
Everolimus damps the immune system, so infections happen more easily, including ones that had been dormant, such as hepatitis B or tuberculosis. Some have been fatal. Fever, chills or a productive cough need assessing rather than waiting out.
Non-infectious pneumonitis is a separate problem: inflammation in the lungs caused by the drug itself, not by a germ. It can be silent on a scan before it causes symptoms. New breathlessness or a dry cough should be reported, not attributed to being tired.
Live vaccines are not advised during treatment, and a normal response to other vaccines may be blunted.
Blood sugar, cholesterol and regular blood tests
Everolimus raises blood sugar, cholesterol and triglycerides in many people. Kidney function and blood counts can also shift. Expect blood tests before starting and at intervals afterwards. If you have diabetes, monitoring is likely to be tightened.
Grapefruit, other medicines and surgery
Grapefruit and grapefruit juice raise everolimus levels and are best avoided completely. So do several antibiotics, antifungals and heart drugs; others lower the level and make it less effective. St John's wort is a common example of the second kind. Show a full list to your pharmacist.
Two more things worth flagging. Wound healing is slower, so tell surgeons and dentists before any procedure. And taken with an ACE inhibitor for blood pressure, the risk of angioedema, a sudden swelling of the face, lips or tongue, rises sharply. That is an emergency.
When to get help sooner
- Call 911 or go to an emergency department if your face, lips or tongue swell up, or your voice changes and breathing tightens. This risk is higher if you also take an ACE inhibitor.
- Get medical care right away — do not wait for the next clinic slot — if your temperature reaches 100.4°F (38°C) or higher, or you get shaking chills. Everolimus damps the immune system, and the CDC treats a fever during cancer treatment as an emergency, because infection can turn serious in hours. Ring your team's urgent number on the way, or go straight to an emergency department.
- Call your care team the same day if you have a cough bringing up phlegm, or you are newly short of breath or coughing dryly.
- Call your care team within a day or two if mouth ulcers stop you eating or drinking properly, or you are suddenly very thirsty, passing lots of urine and losing weight.
Tell any surgeon or dentist that you take everolimus, because wounds heal more slowly on it.
Sources
https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=2150f73a-179b-4afc-b8ce-67c85cc72f04
https://www.cancer.gov/about-cancer/treatment/drugs/everolimus
https://www.cdc.gov/cancer-preventing-infections/patients/fever.html
Words to know
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Common questions
What is Afinitor?
Afinitor (Everolimus) is a targeted therapy called an mTOR inhibitor. It blocks a protein called mTOR that helps cancer cells grow, divide, and form blood vessels. It is used to help treat some breast, kidney, and neuroendocrine cancers.
How is Afinitor given?
It is usually given as tablets taken by mouth each day. It is taken as pills or capsules by mouth, often once or twice a day at home. Take it exactly as prescribed and ask your team before stopping or changing it. The exact schedule is set by your care team.
What are the common side effects of Afinitor?
Commonly reported side effects include mouth sores, tiredness, rash, raised blood sugar or cholesterol, and infections. Not everyone gets them, and many can be managed. Tell your care team about anything new or worsening.
Does Afinitor cure cancer?
That depends on the person, the cancer type, and its stage. For some people a medicine like this can control cancer for a long time or be part of a curative plan; for others the goal is to slow the cancer or ease symptoms. Your care team can explain the goal in your situation.
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Sources last checked: 2026-08-13 what this meansLast updated: 2026-08-19Next planned review: 2027-01-14
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How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes. We do not employ clinicians and do not intend to — our work is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Editorial review complete — This page completed Cancer Explained's editorial checks (sources, safety, plain language, duplication). It has not been reviewed by a physician or other healthcare professional.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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