Care During Chemotherapy and Beyond


Trade Name(s): Koselugo®

Selumetinib is the generic name for the trade name drug Koselugo®. In some cases, health care professional may use the trade name or the generic name when referring to the drug.

Drug Type: Selumetinib is a targeted therapy. This medication is classified as a kinase inhibitor (for more detail, see "How Selumetinib Works" below).

What Selumetinib Is Used For

  • Treatment of pediatric patients 2 years of age and older with neurofibromatosis type 1 (NF1) with symptomatic, inoperable plexiform neurofibromas (PN)

Note: If a drug has been approved for one use, physicians may elect to use this same drug for other problems if they believe it may be helpful.

How Selumetinib Is Given

  • Selumitinib is a capsule, taken by mouth twice daily on an empty stomach. Do not eat 2 hours before or 1 hour after each dose.
  • Take selumetinib at the same time each day, about 12 hours apart. Swallow capsules whole with a glass of water. Do not chew, dissolve or open the capsules.
  • Do not drink grapefruit juice, eat grapefruit or take supplements containing grapefruit or St. John's Wort during treatment with selumetinib.
  • The amount of selumetinib you will receive depends on weight or size (body surface area).
  • Store selumetinib at room temperature, between 68℉ to 77℉ (20℃ to 25℃)
  • The bottle of selumetinib contains a desiccant packet to help reduce moisture. Do not throw away desiccant packet. Keep selumetinib in its original bottle.
  • If you miss a dose of selumetinib, take it as soon as you remember. If it is less than 6 hours before your next scheduled dose, take your next dose at regular time. Do not make up for the missed dose.
  • If you vomit at any time after taking selumetinib, do not take another dose. Take your next dose at the scheduled time.

Side Effects

Important things to remember about the side effects of selumetinib:

  • Most people will not experience all of the selumetinib side effects listed.
  • Selumetinib side effects are often predictable in terms of their onset, duration, and severity.
  • Most selumetinib side effects will improve after therapy is complete.
  • There are many options to minimize or prevent the side effects of selumetinib.

The following side effects are common (occurring in greater than 30%) for patients taking selumetinib:

These are less common side effects (occurring in 10-29%) for patients receiving selumetinib:

These are rare serious side effects for patients receiving selumetinib:

Not all side effects are listed above. Side effects that are very rare - occurring in less than about 10 percent of patients - are not listed here. But you should always inform your health care provider if you experience any unusual symptoms.

When to Contact Your Doctor or Health Care Provider

Contact your health care provider immediately, day or night, if you should experience any of the following symptoms:

  • Fever of 100.4º F (38º C) or higher, chills (possible signs of infection)
  • Signs of heart problems including persistent cough or wheezing, shortness of breath, swelling of your ankles or feet, tiredness or increased heart rate
  • Muscle aches or pain muscle spasms or weakness or dark, reddish urine

The following symptoms require medical attention, but are not an emergency. Contact your health care provider within 24 hours of noticing any of the following:

  • Severe skin changes including rash that covers a large area of your body, peeling skin or blisters
  • Skin infection including redness, pain, swelling, and/or drainage from anywhere on the skin
  • Nausea (interferes with ability to eat and unrelieved with prescribed medication)
  • Vomiting (vomiting more than 4-5 times in a 24-hour period)
  • Diarrhea (4-6 episodes in a 24-hour period)
  • Unusual bleeding or bruising
  • Black or tarry stools, or blood in your stools
  • Blood in the urine
  • Pain or burning with urination
  • Extreme fatigue (unable to carry on self-care activities)
  • Mouth sores (painful redness, swelling or ulcers)

Always inform your health care provider if you experience any unusual symptoms.


  • Before starting selumetinib treatment, make sure you tell your doctor about any other medications you are taking (including prescription, over-the-counter, vitamins, herbal remedies, etc.). Especially notify your health care provider if you are taking aspirin, blood thinners or other medications to treat blood clots or supplements containing vitamin E. Selumetinib contains vitamin E, which may increase your risk of bleeding.
  • Notify your doctor of all your medical conditions especially heart or eye problems.
  • Do not drink grapefruit juice, eat grapefruit or take supplements containing grapefruit or St. John's Wort during treatment with selumetinib.
  • Do not receive any kind of immunization or vaccination without your doctor's approval while taking selumetinib.
  • Inform your health care professional if you are pregnant or may be pregnant prior to starting this treatment. This drug must not be given to a pregnant woman or a woman who intends to become pregnant. If you become pregnant while taking selumetinib, stop taking the medication immediately and call your doctor for further instructions.
  • For both men and women: use contraceptives, and do not conceive a child (get pregnant) while taking selumetinib. Barrier methods of contraception, such as condoms, are recommended during selumetinib treatment and for 1 week after your last dose.
  • Do not breast feed while taking selumetinib and for 1 week after your last dose.

Self-Care Tips

  • Drink at least two to three quarts of fluid every 24 hours, unless you are instructed otherwise.
  • You may be at risk of infection so try to avoid crowds or people with colds, and report fever or any other signs of infection immediately to your health care provider.
  • Wash your hands often.
  • To help treat/prevent mouth sores, use a soft toothbrush, and rinse three times a day with 1 teaspoon of baking soda mixed with 8 ounces of water.
  • Use an electric razor and a soft toothbrush to minimize bleeding.
  • Avoid contact sports or activities that could cause injury.
  • To reduce nausea, take anti-nausea medications as prescribed by your doctor, and eat small, frequent meals.
  • Follow regimen of anti-diarrhea medication as prescribed by your health care professional.
  • Eat foods that may help reduce diarrhea (see managing side effects - diarrhea).
  • Avoid sun exposure. Wear SPF 30 (or higher) sunblock and protective clothing.
  • In general, drinking alcoholic beverages should be kept to a minimum or avoided completely. You should discuss this with your doctor.
  • Get plenty of rest.
  • Maintain good nutrition.
  • Remain active as you are able. Gentle exercise is encouraged such as a daily walk.
  • If you experience symptoms or side effects, be sure to discuss them with your health care team. They can prescribe medications and/or offer other suggestions that are effective in managing such problems.

Monitoring and Testing While Taking Selumetinib

You will be checked regularly by your doctor while you are taking selumetinib, to monitor side effects and check your response to therapy. Periodic blood work will be obtained to monitor your complete blood count (CBC) as well as the function of other organs (such as your kidneys and liver) will also be ordered by your doctor. Heart function and visions tests will also be obtained before and during treatment with selumetinib.

How Selumetinib Works

Cancer is a disease caused by changes, also known as mutations, in DNA that change the way cells grow and divide. Cancer cells can be destroyed using many different types of medications that work in very different ways. Examples of medications that destroy cancer cells include cytotoxic chemotherapy, small molecule inhibitors, monoclonal antibodies, and antibody-drug conjugates.

Targeted therapy is about identifying the other features of cancer cells. Scientists look for specific differences in the cancer cells and the normal cells. This information is used to create a targeted therapy to attack the cancer cells without damaging the normal cells, thus leading to fewer side effects. Many targeted therapies are small molecule drugs. These drugs are small enough to enter the cell and affect other molecules such as proteins or DNA. Each type of targeted therapy works a little bit differently but all interfere with the ability of the cancer cell to grow, divide, repair and/or communicate with other cells.

Selumetinib inhibits mitogen-activated protein kinases 1 and 2 (MEK 1/2). MEK 1/2 proteins are crucial components of the RAF-MEK-ERK pathways, which are often activated in different types of cancers, leading to uncontrolled growth. Selumetinib blocks these pathways to inhibit cellular growth.

Note: We strongly encourage you to talk with your health care professional about your specific medical condition and treatments. The information contained in this website is meant to be helpful and educational, but is not a substitute for medical advice. is designed to provide the latest information about chemotherapy to patients and their families, caregivers and friends. For information about the 4th Angel Mentoring Program visit