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Trade/other name(s): Mekinist

Why would this drug be used?

This drug is used to treat advanced melanomas that have certain mutations (changes) in the BRAF gene. It is also being studied for use against other types of cancers.

How does this drug work?

Trametinib is a type of targeted therapy known as a kinase inhibitor. Kinases are proteins on or near the surface of a cell that transmit important signals to the cell’s control center. When cells have a mutation in a gene called BRAF, it keeps the BRAF signaling pathway active, which constantly tells the cell to grow and divide. Trametinib blocks the kinases MEK1 and MEK2, which are part of this BRAF pathway. Shutting off this pathway helps stop cell growth.

About half of all melanomas have mutations in the BRAF gene. Your doctor will test your cancer cells to be sure they have one of these mutations before starting treatment with this drug.

Before taking this medicine

Tell your doctor…

  • If you are allergic to anything, including medicines, dyes, additives, or foods.
  • If you have any heart problems, including congestive heart failure. This drug can damage the heart (see “Precautions”).
  • If you have high blood pressure. This drug can cause high blood pressure or make existing high blood pressure worse (see “Precautions”).
  • If you have any lung or breathing problems. Rarely, this drug can cause serious lung disease (see “Precautions”).
  • If you have any eye or vision problems. This drug can cause vision changes or even loss of vision in some people (see “Precautions”).
  • If you have any type of liver disease (including hepatitis) or kidney disease. This drug is cleared from the body by the liver and kidneys. If these organs aren’t working well, your doctor might need to watch you more closely during treatment.
  • If you have any other medical conditions such as bleeding problems, gout, or infections. Your doctor may need to monitor you more closely during treatment.
  • If you are pregnant, trying to get pregnant, or if there is any chance of pregnancy. This drug can cause problems with the fetus if taken at the time of conception or during pregnancy. Women who could become pregnant need to follow special precautions if taking this drug (see “Precautions” below).
  • If you are breastfeeding. Although no studies have been done, this drug may pass into breast milk and affect the baby. Breastfeeding is not recommended during treatment with this drug.
  • If you think you might want to have children in the future. This drug might affect fertility. Talk with your doctor about the possible risk with this drug and the options that may preserve your ability to have children.
  • About any other prescription or over-the-counter medicines or supplements you are taking, including vitamins and herbs. In fact, keeping a written list of these (including the doses of each and when you take them) with you in case of emergency may help prevent complications if you get sick.

Interactions with other drugs

This drug is not known to interact directly with other drugs at this time, but this does not necessarily mean that it will not interact with other drugs. It is possible that some medicines or supplements might affect levels of trametinib in the body, or that levels of these drugs might be affected by taking trametinib. This might lead to unwanted side effects or other problems. Make sure your doctor is aware of all of the drugs and supplements you are taking.

Check with your doctor, nurse, or pharmacist about any other medicines, herbs, and supplements you are taking, and whether alcohol can cause problems with this medicine.

Interactions with foods

No interactions with foods are known at this time. Check with your doctor, nurse, or pharmacist about whether any foods might be a problem.

Tell all the doctors, dentists, nurses, and pharmacists you visit that you are taking this drug.

How is this drug taken or given?

Trametinib is taken by mouth as a pill. The usual starting dose is 2 mg (milligrams), taken once a day. The pill should be taken at the same time each day, at least 1 hour before or at least 2 hours after a meal. Your dose may need to be adjusted or delayed if you have side effects.

Take this drug exactly as directed by your doctor. If you do not understand the instructions, ask your doctor or nurse to explain them to you. Keep the medicine in a tightly closed container away from heat and moisture and out of the reach of children and pets.


This drug can cause heart damage in some people. This can lead to congestive heart failure, which can cause symptoms such as a rapid heartbeat, shortness of breath, cough, feeling tired or dizzy, or swelling in the hands or feet. Your doctor will check your heart function with an echocardiogram (ultrasound of the heart) or a MUGA scan before and during treatment to watch for possible heart damage. Tell your doctor or nurse right away if you have any of the symptoms above.

Most people who take this drug will have skin problems, such as rash, redness, infections, or hand-foot syndrome (pain, numbness, tingling, redness, swelling, and possibly skin peeling or sores on the hands or feet). A small portion of people have severe skin problems that might require staying in the hospital. Let your doctor know right away if you notice any of the symptoms above.

A small portion of people might develop severe lung disease during treatment with this drug, which might require them to be in the hospital. Tell your doctor right away if you notice any possible symptoms of lung problems, such as shortness of breath or a new cough.

Trametinib can cause high blood pressure or make it worse. Tell your doctor if you have ever had high blood pressure or are taking medicines for it. Your blood pressure should be checked regularly during treatment. If your blood pressure goes up, you may need to take medicine or adjust your current medicines to help control it. Tell your doctor right away if you notice any possible symptoms of high blood pressure, including a severe headache, chest pain, or feeling dizzy or light-headed.

This drug might cause eye problems in some people, which can range from minor vision changes to blindness. Tell your doctor or nurse right away if you have redness, swelling, or pain in the eyes or if you notice any changes in vision while taking this drug.

This drug can cause diarrhea, which might be severe in some people. Let your doctor or nurse know if you have severe diarrhea while taking this drug.

Women should avoid pregnancy while taking this drug and for at least 4 months after stopping it. This drug can cause problems with the fetus if taken at the time of conception or during pregnancy. Check with your doctor about what kinds of birth control can be used with this medicine. Tell your doctor right away if you become pregnant.

Possible side effects

You will probably not have most of the following side effects, but if you have any tell your doctor or nurse. They can help you understand the side effects and cope with them.


  • Skin rash*
  • Diarrhea*
  • Swelling in the face, arms, or legs
  • Abnormal blood tests suggesting drug may be affecting the liver (Your doctor will discuss the importance of this finding, if any.)
  • Low blood albumin level (Your doctor will discuss the importance of this finding, if any.)
  • Anemia (low red blood cell count)

Less common

  • Mouth sores
  • High blood pressure*
  • Abdominal (belly) pain
  • Bleeding
  • Heart damage*
  • Serious skin problems, such as infections*
  • Dry skin
  • Itching
  • Skin infection around the nails


  • Lung damage*
  • Eye problems*
  • Feeling dizzy
  • Changes in how things taste
  • Slow heart rate
  • Dry mouth
  • Muscle breakdown, which can lead to kidney damage

*See the “Precautions” section for more detailed information.

Other side effects not listed above can also occur in some patients. Tell your doctor or nurse if you develop these or any other problems.

FDA approval

Yes – first approved in 2013

Disclaimer: This information does not cover all possible uses, actions, precautions, side effects, or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for talking with your doctor, who is familiar with your medical needs.

Last Medical Review: 06/12/2013
Last Revised: 06/12/2013