Retevmo (selpercatinib) is a brand-name medication that’s prescribed for certain types of cancer and an identified RET gene mutation. As with other drugs, Retevmo can cause side effects, such as nausea or fatigue.

Retevmo can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who took Retevmo in clinical trials:

  • nausea
  • diarrhea
  • headache
  • fatigue
  • dry mouth
  • edema (swelling in your hands, arms, feet, or legs)

Mild side effects can occur with Retevmo use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Retevmo’s prescribing information.

Mild side effects that have been reported with Retevmo include:

  • nausea
  • diarrhea
  • headache
  • edema (swelling in your hands, arms, feet, or legs)
  • fatigue
  • dry mouth
  • high or low blood sugar
  • skin rash
  • increased cholesterol levels
  • constipation
  • changes in certain electrolytes in your blood, such as potassium, sodium, or calcium

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you develop a side effect while taking Retevmo and want to tell the FDA about it, visit MedWatch.

Retevmo may cause serious side effects. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Retevmo’s prescribing information.

If you develop serious side effects while taking Retevmo, 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.

Serious side effects that have been reported and their symptoms include:

For more information about this side effect, see “Side effect specifics.”

ALLERGIC REACTION

For some people, Retevmo can cause an allergic reaction.

In general, symptoms of allergic reaction can be mild or serious.

Ways to manage

For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.

For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to Retevmo, your doctor may recommend taking a different medication instead.

Retevmo may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

How long will I take Retevmo?

Revetmo is typically prescribed long term. You’ll likely take Retemvo unless your cancer starts to worsen or you have side effects that are severe or can’t be managed. Your doctor will monitor your blood tests for side effects that may not be causing any symptoms.

Talk with your doctor if you have bothersome side effects. They can recommend ways to help lessen your side effects.

Do I need to stop Retevmo if I’m going to have surgery?

Yes, your doctor will likely have you stop taking Retevmo at least 7 days before your surgery. If you have a major surgery, you’ll need to wait 2 weeks after surgery before you start taking Retevmo again. Your doctor will also want to make sure your wounds are adequately healed before you restart Retevmo. This is because Retevmo can cause your wounds to heal slower than usual.

Talk with your doctor if you have any questions about stopping Retevmo if you plan to have surgery.

Learn more about some of the side effects that Retevmo may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Retevmo.

Liver problems

Retevmo can cause an increase in the levels of liver enzymes in your blood. This was a common side effect reported in clinical studies of Retevmo. Increased liver enzymes may indicate that your liver isn’t working as well as it should. An increase in liver enzymes can happen within days to years after starting treatment with Retevmo.

High liver enzymes can happen at any time after starting treatment with Retevmo. In some cases, an increase in liver enzymes may indicate serious liver damage. Symptoms of liver damage may include:

  • abdominal pain
  • dark urine
  • swollen ankles or legs
  • loss of appetite
  • jaundice (yellowing of the skin or whites of the eyes)

What you can do

Your doctor will order a blood test called a liver function test before starting treatment with Retevmo. This test measures your liver enzymes and evaluates the health of your liver. They’ll also check your liver enzymes regularly while you’re taking Retevmo.

If you develop high liver enzymes, your doctor may have you temporarily stop taking Retevmo until your liver enzymes come down to a regular level. When you start taking Retevmo, your doctor may restart you on a lower dose. If your liver problems are severe, your doctor will likely switch you to a different medication.

If you have symptoms of liver problems, be sure to talk with your doctor right away.

Bleeding problems

Bleeding problems are a common side effect of Retevmo reported in the drug’s clinical trials. In rare cases, bleeding can be serious and even fatal.

Retevmo can also commonly cause low platelet levels. Platelets are a type of cell that helps your blood clot. Low platelet levels can increase your risk of bleeding problems.

Symptoms of bleeding problems may include:

  • coughing up blood
  • sudden, severe headache
  • changes in vision
  • nosebleeds
  • blood in your stool or urine
  • bruising more easily than usual
  • bleeding between periods

What you can do

If you have any symptoms of bleeding, contact your doctor right away. They may want to do a blood test to check your platelet levels. If you have minor bleeding, your doctor may have you temporarily stop taking Retevmo until the bleeding stops.

If you have severe bleeding or feel like your symptoms are life threatening, call 911 or your local emergency number.

Below is important information you should consider before taking Retevmo.

Before taking Retevmo, discuss your health history with your doctor. Retevmo may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you:

  • high blood pressure
  • bleeding problems
  • liver problems
  • lung or breathing problems
  • heart problems, including long QT syndrome
  • scheduled surgery
  • previous allergic reaction to Retevmo or a similar drug
  • pregnancy
  • breastfeeding

Disclaimer: Medical News Today 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.