Hi @ehb999, Welcome to Connect. I see you did find another string regarding Keytruda.
I looked for a study with the percentages of participants with each side effect, but I'm not finding one yet. I'll keep looking.
You may have the official medication insert already, but this is what I've found so far (https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/125514s037lbl.pdf):
"What are the possible side effects of KEYTRUDA?
KEYTRUDA can cause serious side effects. See “What is the most important information I should know about
KEYTRUDA?”
Common side effects of KEYTRUDA when used alone include: feeling tired, pain, including pain in muscles, bones or
joints and stomach-area (abdominal) pain, decreased appetite, itching, diarrhea, nausea, rash, fever, cough, shortness of
breath, and constipation.
Common side effects of KEYTRUDA when given with certain chemotherapy medicines include: feeling tired or weak,
nausea, constipation, diarrhea, decreased appetite, rash, vomiting, cough, trouble breathing, fever, hair loss, and
inflammation of the nerves that may cause pain, weakness, and paralysis in the arms and legs.
In children, feeling tired, vomiting and stomach-area (abdominal) pain, and increased levels of liver enzymes and
decreased levels of salt (sodium) in the blood are more common than in adults.
These are not all the possible side effects of KEYTRUDA. For more information, ask your doctor or pharmacist. "

Have you had other treatments or surgery, or are you starting with Keytruda as an initial treatment?
What is your PDL-1 level?