What side effects does Keytruda (pembrolizumab) cause?
Keytruda can cause side effects that range from mild to serious. Because it works by boosting the immune system, many of its key side effects are immune-related and can affect organs like the lungs, colon, liver, skin, and endocrine glands [1].
What are the most common Keytruda side effects?
Commonly reported side effects include fatigue and other effects that can occur during treatment [1]. Patients may also experience symptoms related to immune activation, such as rash or inflammation-related symptoms (for example, diarrhea/colitis symptoms or shortness of breath), depending on which organ is affected [1].
What are the serious immune-related side effects people worry about?
Serious immune-related adverse events can occur, including inflammation that may require prompt treatment and sometimes stopping Keytruda. These can involve:
- Lungs (pneumonitis), which can cause cough or breathing problems [1]
- Colon or intestines (colitis), which can cause persistent diarrhea or abdominal pain [1]
- Liver (hepatitis), which can cause abnormal liver tests and sometimes jaundice [1]
- Hormone glands (endocrinopathies), which can lead to thyroid problems or other hormone imbalances [1]
- Skin reactions, including severe rash [1]
When do Keytruda side effects happen?
Side effects can occur during treatment and sometimes after stopping. Immune-related events can appear at different times, so clinicians advise close monitoring for new or worsening symptoms throughout care [1].
What should patients watch for and report immediately?
Patients should seek urgent medical advice for symptoms that could signal organ inflammation, such as:
- Trouble breathing or new/worsening cough
- Severe or persistent diarrhea, or blood in stool
- Severe abdominal pain
- Yellowing of the skin/eyes or dark urine
- Severe rash, blistering, or widespread skin pain
- Severe weakness, confusion, severe headache, or fainting (possible serious endocrine or neurologic effects)
These symptoms can signal serious immune-related toxicity and need fast evaluation [1].
How are Keytruda side effects treated?
Treatment depends on the type and severity of side effects. Management often involves holding or stopping Keytruda and using therapies such as corticosteroids and other immune-suppressing treatments when an immune-related adverse event is suspected or confirmed [1].
Does Keytruda cause different side effects for different cancers?
Keytruda’s side effect profile is broadly similar across approved uses, but the overall pattern can vary based on what other therapies are combined with it (for example, chemotherapy or other immunotherapies) and the underlying condition being treated [1].
Where can I find the official side-effect information?
The prescribing information (and patient-facing information) is the most direct source for Keytruda adverse reactions and warnings, including immune-related side effects [1]. DrugPatentWatch.com can also be used to track Keytruda-related regulatory and patent context, though it is not the primary source for side-effect warnings.
Sources cited:
1. https://www.drugs.com/keytruda.html