Retevmo is a treatment option for certain types of cancer.

Retevmo is a medication that is used to treat certain types of cancer.

The active ingredient in Retevmo is selpercatinib. An active ingredient is what makes a drug work.

Retevmo is a capsule that you swallow. If Retevmo is safe and effective for you, your doctor will recommend you take it for a long time.

For more information about Retevmo, including details about its uses, see this in-depth article.

Retevmo can cause mild to serious side effects. Continue reading to learn more.

Some people may experience side effects during their treatment. Retevmo has been reported to have some side effects.

The side effects explained section is where you can learn more about this side effect.

Mild side effects have been reported with Retevmo.

The side effects explained section is where you can learn more about this side effect.

These side effects should be temporary. Some may be easy to manage. If you have any symptoms that bother you, talk to your doctor or pharmacist. Unless your doctor recommends it, you should not stop taking Retevmo.

Retevmo may cause mild side effects other than the ones listed above. See the Retevmo prescribing information for details.

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

It is possible to experience serious side effects from Retevmo, though most are mild. There have been serious side effects reported with Retevmo.

The side effects explained section is where you can learn more about this side effect.
† An allergic reaction is possible after using Retevmo. But it’s not clear whether this side effect occurred in studies.

If you develop serious side effects while taking Retevmo, call your doctor. If the side effects seem life threatening or you think you have a medical emergency, immediately call the emergency number.

Some children are treated for medullary thyroid cancer with the help of Retevmo. The side effects of Retevmo are similar to those of adults.

It is possible for Retevmo to cause bone growth problems in children who are still growing. Retevmo should only be used in children 12 years and older.

“If your child is taking Retevmo, their doctor will be able to check their growth. The doctor may keep an eye on your child’s growth. If growth problems occur, they may recommend pausing or stopping Retevmo treatment.”

Some of the side effects Retevmo may cause are discussed.

Increased liver enzyme levels or liver problems

You may have increased levels of liver enzymes in your blood during your treatment with Retevmo. In studies, this was a common side effect reported by people taking Retevmo.

An increase in liver enzymes in the blood may indicate liver problems. In some cases, these problems can be serious.

If you know the symptoms of a problem with the liver, you can tell a doctor right away. Symptoms may include:

What might help

Before you start treatment with Retevmo, your doctor will check your liver enzyme levels through liver function tests. Then they’ll monitor your liver enzyme levels throughout treatment to be sure they do not increase.

If you have any symptoms, tell your doctor. If your blood levels are high, they can order a blood test.

“If you develop a problem with your body’s immune system, your doctor may recommend a reduction in your Retevmo dose. In some cases, your doctor may recommend a different medication to treat your condition, if he stops your treatment with Retevmo.”

Diarrhea

Diarrhea was one of the more commonly reported side effects in studies of Retevmo. You may have diarrhea if your bowel movements are happening more often than usual. Feeling urgency to have a bowel movement is another symptom of this side effect.

What might help

If you’re experiencing diarrhea during your treatment with Retevmo, tell your doctor. In some cases, they may be able to recommend medications to treat this side effect. An example is Imodium (loperamide). They will likely also recommend that you stay hydrated, since diarrhea can cause dehydration.

Skin rash

You may develop a rash from taking Retevmo. This was a common side effect in studies of this medication. Symptoms of a rash may include:

  • Your skin is red or dark.
  • bumps or hives
  • It was itching.

What might help

If you notice a rash during your treatment with Retevmo, tell your doctor. In some cases, rash can be a symptom of a more serious side effect, such as an allergic reaction.

Your doctor can determine what is causing your rash. They may be able to recommend a medication to help you.

Increase in cholesterol levels

Retevmo may cause an increase in your cholesterol levels. In studies, this was a common side effect reported by people taking the medication.

What might help

During treatment with Retevmo, your doctor will likely monitor your cholesterol levels through blood tests. If you develop high cholesterol, your doctor may recommend taking a medication to decrease your cholesterol levels.

Allergic reaction

Like most drugs, Retevmo can cause an allergic reaction in some people. But it’s not clear whether this side effect occurred in studies.

Mild to serious symptoms can be present.

  • There is a skin rash.
  • It is itchy.
  • flushing (temporary warmth, redness, or deepening of skin color)
  • “It’s usually under your skin, but it can be anywhere.”
  • It can be hard to breathe if you have swelling of your mouth, tongue, or throat.

What might help

If you have a mild rash, call your doctor. They may suggest a treatment to help you. Examples include:

  • an over-the-counter antihistamine you swallow, such as Benadryl (diphenhydramine)
  • You apply a product to your skin.

If your doctor confirms you have an allergic reaction to Retevmo, they will decide if you should continue taking it.

If you have a severe allergic reaction, you should call the emergency number. These symptoms could be life threatening and need immediate medical care.

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

Keeping track of side effects

Take notes on any side effects you are having during your Retevmo treatment. You can share this information with your doctor. This is helpful when you are starting to use a combination of treatments.

Side effect notes can include things.

  • When you had the side effect, what dose of the drug was taking?
  • How soon did you experience the side effect?
  • What are your symptoms?
  • How did it affect your daily activities?
  • What other drugs were you taking?
  • Other information is important to you.

Sharing notes with your doctor will help them understand how Retevmo affects you. If needed, they can use this information to adjust your treatment plan.

If you have certain medical conditions, Retevmo may not be right for you. These are drug-condition interactions. Other factors may affect whether Retevmo is a good option.

Before starting Retevmo, you should talk to your doctor about your health history. The list has factors to consider.

Liver problems. Retevmo may increase your liver enzyme levels, possibly causing liver problems. If you already have liver problems, Retevmo may make your condition worse.

Tell your doctor about conditions affecting your liver before starting Retevmo. In some cases, your doctor may recommend using a lower dose of Retevmo. They will likely monitor your liver function through blood tests while you’re taking Retevmo. If your liver problems worsen, your doctor may recommend a different treatment option for you.

Allergic reaction. If you’ve had an allergic reaction to Retevmo or any of its ingredients, your doctor will likely not prescribe Retevmo. Ask them what other medications are better options for you.

High blood pressure. Retevmo can cause high blood pressure.. If you already have high blood pressure., this medication may make your condition worse. Before you start taking Retevmo, tell your doctor if you have high blood pressure.. They may monitor your blood pressure throughout treatment as well as recommend that you take blood pressure medication.

Heart problems, especially long QT syndrome. If you have any heart problems, tell your doctor before Retevmo treatment. This medication can cause long QT syndrome. If you already have a heart problem or long QT syndrome, this medication may make your condition worse. Your doctor may recommend treating your heart condition before you start taking Retevmo.

Bleeding problems. Retevmo may increase your risk of There was bleeding.. If you have any There was bleeding. disorders, such as a blood clotting problem, tell your doctor before starting Retevmo treatment. This medication may make your condition worse. Your doctor will be able to determine if it may be safe for you to take Retevmo.

Upcoming surgery. Retevmo can hinder your body’s healing ability. This means it may take longer to heal than usual. If you have any upcoming surgeries planned, tell your doctor before starting Retevmo. They can help you determine how to take Retevmo around the time of your surgery.

They may recommend stopping treatment 7 days before surgery. For certain surgeries, they may pause treatment for a couple of weeks so your body can heal.

Alcohol and Retevmo

There are no known interactions between alcohol and Retevmo. It is possible that the side effects of Retevmo may become worse if you drink alcohol during treatment.

Retevmo can cause problems with the liver. Alcohol can increase your risk of developing a problem with the bile duct. It is possible that drinking alcohol during Retevmo treatment will increase this risk.

“Talk to your doctor to find out if it’s safe to drink while taking Retevmo.”

Pregnancy and breastfeeding while taking Retevmo

Retevmo should not be taken during pregnancies or breastfeeding.

At this time, there haven’t been any studies of Retevmo during pregnancy. But due to the way the drug works, it may cause problems with fetal development (commonly known as birth defects). It may also result in loss of pregnancy. If you can become pregnant, your doctor will have you take a pregnancy test to confirm that you are not pregnant before starting Retevmo treatment.

Birth control is recommended for females who can become pregnant after taking the last dose of Retevmo. For partners who can become pregnant, males should use contraception for at least 1 week after the last dose.

It is not known if Retevmo is present in breast milk or what effects it may have on a breastfeeding baby. It is not recommended to feed your baby while taking Retevmo or for at least 1 week after stopping treatment.

If you are pregnant or breastfeeding, you should talk with your doctor before starting treatment with Retevmo.

* In this article, we use the terms “male” and “female” to refer to someone’s sex assigned at birth. For information about the difference between sex and gender, see this article.

Side effects may occur during treatment with Retevmo. Side effects from this medication are mild. It is possible to experience serious side effects.

Discuss your risk of side effects with your doctor before starting treatment. Some questions may help you get started.

  • How can I treat side effects from Retevmo?
  • What should I do if I become pregnant while taking Retevmo?
  • Do my other drugs increase my risk of side effects?

Q:

Will I need to have blood tests to monitor for certain side effects during treatment with Retevmo?

Anonymous

A:

Your doctor will recommend blood tests during your treatment. This is to watch for possible side effects from taking Retevmo.

Before you start taking Retevmo, your doctor will check your liver function through blood tests. They will have you get these tests every 2 weeks for the first 3 months of treatment. After that, you will go for blood tests every month or if you develop symptoms of liver problems.

Your doctor will monitor your side effects through other blood tests.

Tell your doctor if you have any side effects from taking Retevmo. They may recommend more tests.

The Healthline Pharmacist TeamAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

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.