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Generic Name: pembrolizumab (PEM broe LIZ ue mab)
Brand Name: Keytruda

Medically reviewed by on Jul 2, 2019 – Written by Cerner Multum

What is pembrolizumab?

Pembrolizumab is a cancer medicine that is used to treat:

  • skin cancer (melanoma or Merkel cell carcinoma);

  • certain types of lung cancer;

  • head and neck cancer;

  • classical Hodgkin lymphoma;

  • primary mediastinal large B-cell lymphoma;

  • a certain type of bladder and urinary tract cancer;

  • a type of cancer that laboratory testing proves to have certain specific DNA mutations, including colorectal cancer;

  • a certain type of cervical cancer;

  • advanced stomach cancer; or

  • a certain type of liver cancer.

Pembrolizumab is often given when the cancer has spread to other parts of the body or cannot be surgically removed, or when other cancer treatments did not work or have stopped working.

For some types of cancer, pembrolizumab is given only if your tumor tests positive for "PD-L1", or if the tumor has a specific genetic marker (an abnormal "EGFR," "ALK," or "HER2/neu" gene).

Pembrolizumab may also be used for purposes not listed in this medication guide.

Important Information

Pembrolizumab can cause side effects in many different parts of your body. Some side effects may need to be treated with other medicine, and your cancer treatments may be delayed. You will need frequent medical tests to help your doctor determine if it is safe for you to keep receiving pembrolizumab.

Call your doctor at once if you have: chest pain, cough, shortness of breath, severe muscle pain or weakness, diarrhea and severe stomach pain, blood in your stools, bruising or bleeding, dark urine, yellowing of the skin or eyes, a hormonal disorder (frequent headaches, feeling light-headed, rapid heartbeats, a deeper voice, increased thirst or urination, feeling cold, weight gain or loss), or a change in the amount or color of your urine.

Before taking this medicine

Tell your doctor if you have ever had:

You may need to have a negative pregnancy test before starting this treatment. Do not use pembrolizumab if you are pregnant. It could harm the unborn baby. Use effective birth control to prevent pregnancy while you are using pembrolizumab and for at least 4 months after your last dose. Tell your doctor right away if you become pregnant.

Do not breast-feed while using pembrolizumab, and for at least 4 months after your last dose.

How is pembrolizumab given?

Your doctor will perform a blood test to make sure pembrolizumab is the right treatment for your condition.

Pembrolizumab is given as an infusion into a vein, usually once every 3 weeks. A healthcare provider will give you this injection.

This medicine must be given slowly, and the infusion can take at least 30 minutes to complete.

You will need frequent medical tests to help your doctor determine if it is safe for you to keep receiving pembrolizumab. Do not miss any follow-up visits.

What happens if I miss a dose?

Call your doctor for instructions if you miss an appointment for your pembrolizumab injection.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while receiving pembrolizumab?

pembrolizumab can pass into body fluids (urine, feces, vomit). For at least 48 hours after you receive a dose, avoid allowing your body fluids to come into contact with your hands or other surfaces. Caregivers should wear rubber gloves while cleaning up a patient's body fluids, handling contaminated trash or laundry or changing diapers. Wash hands before and after removing gloves. Wash soiled clothing and linens separately from other laundry.

Pembrolizumab side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Some side effects may occur during the injection. Tell your caregiver if you feel dizzy, light-headed, itchy, hot, sweaty, chilled, or have trouble breathing.

Pembrolizumab affects your immune system, and can cause side effects in many different parts of your body. Some side effects may need to be treated with other medicine. Your cancer treatments may be delayed or permanently discontinued if you have certain side effects.

Call your doctor at once if you have:

  • new or worsening cough, chest pain, shortness of breath;

  • pale skin, easy bruising or bleeding;

  • numbness, tingling, burning pain, redness, rash, or blisters on your hands or feet;

  • severe muscle weakness, severe or ongoing muscle aches, joint pain;

  • diarrhea or increased stools, severe stomach pain, bloody or tarry stools;

  • a change in the amount or color of your urine;

  • liver problems--loss of appetite, right-sided stomach pain, easy bruising or bleeding, dark urine, jaundice (yellowing of the skin or eyes);

  • low levels of sodium in the body--confusion, slurred speech, severe weakness, loss of coordination, feeling unsteady; or

  • signs of a hormonal disorder--frequent or unusual headaches, feeling light-headed, rapid heartbeats, hoarse or deepened voice, increased hunger or thirst, increased urination, constipation, hair loss, muscle pain, sweating, feeling cold, weight changes.

Common side effects (some are more likely with combination chemotherapy) may include:

  • nausea, vomiting, stomach pain, loss of appetite, diarrhea, constipation;

  • low sodium levels, abnormal liver or thyroid function tests;

  • fever, feeling weak or tired;

  • cough, hoarse voice, feeling short of breath;

  • itching, rash, hair loss;

  • increased blood pressure;

  • pain in your muscles, bones, or joints; or

  • soreness in or around your mouth, nose, eyes, throat, or vagina.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect pembrolizumab?

Other drugs may affect pembrolizumab, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.