How long do side effects last?
Most side effects go away over time after treatment ends and the healthy cells recover. The time it takes to get over some side effects varies from person to person. It depends on many factors, including your overall health and the drugs you were given.
Because many targeted drugs are still quite new, it’s hard to say how long you can expect side effects to last. We do know that some of the side effects from standard chemo drugs can last a lifetime, such as when the drug causes long-term damage to the heart, lungs, kidneys, or reproductive organs. In many cases we still don’t know if targeted therapy drugs cause these kinds of long-term changes.
Skin problems from targeted cancer therapy drugs
Many targeted therapy drugs cause a rash or other skin changes. These skin problems usually develop slowly over days to weeks. They are not signs of a drug allergy.
In contrast, allergic reactions to drugs tend to start suddenly, usually within minutes to hours after taking the drug. They may include hives (raised skin welts that often go away in a day or so) and intense itching. An allergic reaction often includes other serious symptoms such as trouble breathing, dizziness, tightness in the throat or chest, or swelling of the lips or tongue. If you have these kinds of symptoms, get emergency help and call your doctor right away.