Mektovi (binimetinib) is a prescription drug that’s used to treat certain types of cancer. Mektovi can cause side effects that range from mild to serious. Examples include nausea, diarrhea, and vomiting.

Mektovi is used in combination with encorafenib (Braftovi) to treat the following types of cancer in adults:

Specifically, Mektovi is prescribed to treat cancers that have gene mutations (atypical changes) called BRAF V600E or V600K.

The active ingredient in Mektovi is binimetinib. The drug comes as an oral tablet.

Keep reading to learn about the common, mild, and serious side effects that Mektovi can cause. For a general overview of the drug, including details about its uses, see this article.

Some people may experience mild to serious side effects when taking Mektovi with Braftovi. Examples of these commonly reported side effects include:

Mild side effects have been reported when taking Mektovi with Braftovi. These include:

  • vomiting
  • fever
  • nausea
  • abdominal pain
  • diarrhea
  • constipation
  • fatigue
  • rash
  • dizziness

In most cases, these side effects should be temporary. And some may be easily managed. But if you have symptoms that are ongoing or bothersome, talk with your doctor or pharmacist. And do not stop taking Mektovi unless your doctor recommends it.

Mektovi may cause mild side effects other than those listed above. See the drug’s prescribing information for details.

Serious side effects have been reported when taking Mektovi with Braftovi. These include:

If you develop serious side effects while taking Mektovi, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

* To learn more about this side effect, see the “Side effects explained” section below.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Mektovi, visit MedWatch.

Allergic reaction

For some people, Mektovi can cause an allergic reaction.

But it’s not clear whether this side effect occurred in the drug’s studies.

In general, symptoms of an allergic reaction can be mild or serious. You can learn more about possible symptoms in this article.

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms and can determine whether you should keep taking Mektovi.

If you have symptoms of a severe allergic reaction, such as swelling or difficulty breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Mektovi, they may have you switch to a different treatment.

Learn more about some of the side effects Mektovi may cause.

Blood clots

Blood clots were a serious side effect reported in studies of Mektovi. These blood clots can develop in any part of your body. Therefore, the symptoms you experience will depend on where the blood clot is located.

Blood clots that develop in the lower parts of your body may cause symptoms such as:

  • foot and ankle swelling
  • calf and thigh pain and soreness
  • discoloration and warmth in the affected area

Blood clots that develop in your lungs may cause symptoms such as:

  • fast breathing or heart rate
  • chest pain or discomfort
  • difficulty breathing or shallow breathing

What might help

Talk with your doctor right away if you’re experiencing any symptoms of a blood clot. Call 911 or your local emergency number right away if you feel these symptoms are life threatening or you think you’re having a medical emergency.

Your doctor will treat the blood clot and may have you switch to a new treatment instead of Mektovi.

Hemorrhage

Hemorrhage (severe bleeding) is a serious side effect reported in studies of Mektovi. Hemorrhage symptoms can include:

  • blood in the urine
  • coughing up blood
  • blood in the eyes

What might help

Talk with your doctor right away if you’re experiencing these symptoms. Call 911 or your local emergency number right away if you feel these symptoms are life threatening or you think you’re having a medical emergency.

Your doctor will treat the hemorrhage and may have you switch to a new treatment instead of Mektovi.

Keeping track of side effects

During your Mektovi treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start taking a new drug or using a combination of treatments.

Your side effect notes can include things such as:

  • what dose of the drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • how your symptoms affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help them learn more about how Mektovi affects you. They can then use this information to adjust your treatment plan if needed.

Below is important information you should consider before taking Mektovi.

Warnings

Mektovi can sometimes cause harmful effects in people who have certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether Mektovi is a good treatment option for you.

Talk with your doctor about your health history before you take Mektovi. Be sure to tell them if any of the following factors apply to you:

  • heart problems, such as cardiomyopathy
  • liver problems
  • lung or breathing problems
  • eye problems
  • high blood pressure
  • blood clots
  • bleeding problems
  • rhabdomyolysis (breakdown of damaged skeletal muscle)
  • previous allergic reaction to Mektovi
  • pregnancy
  • breastfeeding

Alcohol and Mektovi

There are no known interactions between alcohol and Mektovi. But, Mektovi can affect your liver and decrease your liver function. Thus, drinking alcohol while taking Mektovi may increase your risk of liver damage.

If you have questions about consuming alcohol during Mektovi treatment, talk with your doctor or pharmacist.

Pregnancy and breastfeeding with Mektovi

Before starting Mektovi treatment, it’s important to talk with your doctor if you’re pregnant, breastfeeding, or planning to become pregnant or to breastfeed.

Pregnancy

Based on how it works, Mektovi should not be taken during pregnancy due to the risk of fetal harm. No information was available in studies on the use of Mektovi during pregnancy. If you’re pregnant or planning to become pregnant, talk with your doctor about your treatment options.

If you’re able to become pregnant, your doctor may recommend using a form of birth control during your Mektovi treatment. You may also need to continue taking birth control for 30 days after taking your last Mektovi dose.

Mektovi is also typically taken with Braftovi. For information on taking Braftovi during pregnancy, please see the prescribing information.

Breastfeeding

It is not recommended to take Mektovi while breastfeeding or for 3 days after your last dose. No information was provided in studies on whether Metovi passes into the breastmilk. However, Mektovi can potentially cause serious side effects in a child who is breastfed. If you’re breastfeeding or planning to do so, talk with your doctor about your options.

Mektovi is also typically taken with Braftovi. For information on taking Braftovi during breastfeeding, please see the prescribing information.

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.