Classification: monoclonal antibody
About Pembrolizumab (Keytruda®)
Pembrolizumab is a type of monoclonal antibody therapy, which works by stimulating the immune system to destroy cancer cells. It binds to the "programmed death receptor" (PD1) found on cells, leading to an anti-tumor immune response.
How to Take Pembrolizumab
Pembrolizumab is administered intravenously (directly into a vein) over 30 minutes once every three weeks. The actual dosage depends upon the patient’s height and weight.
Possible Side Effects of Pembrolizumab
There are a number of things you can do to manage the side effects of pembrolizumab. Talk to your doctor or nurse about these recommendations. They can help you decide what will work best for you. These are some of the most common side effects:
Pembrolizumab activates the immune system with the goal of attacking cancer cells. However, your immune system can also attack healthy tissues and organs. These reactions can cause severe complications and can be fatal in rare cases. It is very important to report symptoms of these problems to your oncology team immediately. These reactions may be treated with corticosteroids (i.e. prednisone) and/or holding the dose of pembrolizumab. Let your healthcare provider know if you have ever been diagnosed with an immune disorder (i.e. Crohn's disease, lupus).
The most concerning problems related to this immune response include:
- Pneumonitis (inflammation of the lungs): symptoms include shortness of breath, chest pain and new or worsening cough.
- Colitis (inflammation of the colon) and bowel perforation (tear or hole in the bowel): symptoms of colitis include cause abdominal pain, diarrhea, cramping and blood in the stool, with or without fever. Bowel perforation can cause abdominal pain and bloating.
- Hepatitis (liver problems): symptoms include yellowing of the skin or whites of the eyes, darkly colored urine, nausea and vomiting, abdominal pain, bleeding and abnormal bruising.
- Abnormalities in thyroid, pituitary or adrenal gland: symptoms include rapid heart rate, weight gain or loss, sweating or feeling cold, hair loss, constipation, persistent or unusual headache, extremity weakness, dizziness, fainting and vision changes.
- Renal failure (kidney failure) or Nephritis (inflammation of the kidneys): symptoms include a change in the amount or color of your urine.
- Report any rash, changes in eyesight, muscle weakness or persistent muscle or joint pain as these can be signs of problems in other organs.
In some cases, patients can have an allergic reaction to this medication. Signs of a reaction can include: shortness of breath or difficulty breathing, chest pain, rash, flushing or itching or a decrease in blood pressure. If you notice any changes in how you feel during the infusion, let your nurse know immediately. The infusion will be slowed or stopped if this occurs.
Nausea and/or Vomiting
Talk to your doctor or nurse so they can prescribe medications to help you manage nausea and vomiting. In addition, dietary changes may help. Avoid things that may worsen the symptoms, such as heavy or greasy/fatty, spicy or acidic foods (lemons, tomatoes, oranges). Try antacids, (e.g. milk of magnesia, calcium tablets such as Tums), saltines, or ginger ale to lessen symptoms.
Call your doctor or nurse if you are unable to keep fluids down for more than 12 hours or if you feel lightheaded or dizzy at any time.
Decrease in Appetite
Nutrition is an important part of your care. Cancer treatment can affect your appetite and, in some cases, the side effects of treatment can make eating difficult. Ask your nurse about nutritional counseling services at your treatment center to help with food choices.
- Try to eat five or six small meals or snacks throughout the day, instead of 3 larger meals.
- If you are not eating enough, nutritional supplements may help.
- You may experience a metallic taste or find that food has no taste at all. You may dislike foods or beverages that you liked before receiving cancer treatment. These symptoms can last for several months or longer after treatment ends.
- Avoid any food that you think smells or tastes bad. If red meat is a problem, eat chicken, turkey, eggs, dairy products and fish without a strong smell. Sometimes cold food has less of an odor.
- Add extra flavor to meat or fish by marinating it in sweet juices, sweet and sour sauce or dressings. Use seasonings like basil, oregano or rosemary to add flavor. Bacon, ham and onion can add flavor to vegetables.
Your oncology team can recommend medications to relieve diarrhea. Also, try eating low-fiber, bland foods, such as white rice and boiled or baked chicken. Avoid raw fruits, vegetables, whole grain breads, cereals and seeds. Soluble fiber is found in some foods and absorbs fluid, which can help relieve diarrhea. Foods high in soluble fiber include: applesauce, bananas (ripe), canned fruit, orange sections, boiled potatoes, white rice, products made with white flour, oatmeal, cream of rice, cream of wheat, and farina. Drink 8-10 glasses on non-alcoholic, un-caffeinated fluid a day to prevent dehydration.
Fatigue is very common during cancer treatment and is an overwhelming feeling of exhaustion that is not usually relieved by rest. While on cancer treatment, and for a period after, you may need to adjust your schedule to manage fatigue. Plan times to rest during the day and conserve energy for more important activities. Exercise can help combat fatigue; a simple daily walk with a friend can help. Talk to your healthcare team for helpful tips on dealing with this side effect.
There are several things you can do to prevent or relieve constipation. Include fiber in your diet (fruits and vegetables), drink 8-10 glasses of non-alcoholic fluids a day, and keep active. A stool softener once or twice a day may prevent constipation. If you do not have a bowel movement for 2-3 days, you should contact your healthcare team for suggestions to relieve the constipation.
Muscle or Joint Pain/Aches and Headache
Your doctor or nurse can recommend medication and other strategies to relieve pain.
Skin changes associated with pembrolizumab include itching and rash. Be sure to report any rash to your healthcare provider. Use a moisturizer on your skin and lips, but avoid moisturizers with perfumes or scents. Your doctor or nurse can recommend medication if itching is bothersome. If your skin does crack or bleed, be sure to keep the area clean to avoid infection.
Exposure of an unborn child to this medication could cause harm to the fetus, so you should not become pregnant or father a child while on this medication or for 4 months following the last dose. Effective birth control is necessary during treatment, even if your menstrual cycle stops or you believe you are not making sperm, you could still be fertile and conceive. A woman should stop breastfeeding while being treated with pembrolizumab since it is unknown if the medication is excreted through breast milk.