Retevmo (selpercatinib) is a brand-name drug prescribed for certain types of cancer in adults and some children. Retevmo comes as an oral capsule that’s typically taken twice per day, but the dosage can vary.

Retevmo is approved by the Food and Drug Administration (FDA) to treat certain cancers with changes in the RET gene. For more information about the specific cancers this drug is used to treat, see the “Retevmo dosage” section below.

Retevmo belongs to a drug class called RET inhibitors. Retevmo isn’t available in a generic version.

Keep reading for specific information about the dosage of Retevmo, including its strengths and how to take the medication. For a comprehensive look at Retevmo, including details about its uses, see this article.

Note: This article describes typical dosages for Retevmo provided by the drug’s manufacturer. When taking Retevmo, always follow the dosage prescribed by your doctor.

The information below describes Retevmo’s recommended dosages and other details about the drug.

Retevmo form

Retevmo comes as an oral capsule.

Retevmo strengths

Retevmo comes in two strengths: 40 milligrams (mg) and 80 mg.

Typical dosages

The following information describes dosages that are commonly prescribed or recommended in adults. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs. If you have questions about your specific dosage, talk with your doctor.

Note that recommended Retevmo dosages are based on body weight in kilograms (kg). For reference, 1 kg equals about 2.2 pounds (lb).

Dosage for non-small cell lung cancer

Doctors may prescribe Retevmo to treat locally advanced or metastatic non-small cell lung cancer (NSCLC) with a RET gene fusion. “Locally advanced” means the cancer has spread to nearby tissues. “Metastatic” means it has spread to other parts of the body.

If your doctor prescribes Retevmo, you’ll likely take the recommended dosage for NSCLC. If you weigh less than 50 kg (less than about 110 lb), your dose will be 120 mg. If you weigh 50 kg or more, your dose will be 160 mg. You’ll take your dose twice daily, about 12 hours apart.

Dosage for solid cancerous tumors

Retevmo is also approved to treat locally advanced or metastatic solid cancerous tumors with a RET gene fusion. For this use, the cancer must also have worsened or returned despite other treatments, or there are no other treatment options.

If your doctor prescribes Retevmo for your cancer, you’ll likely take the recommended dosage. If you weigh less than 50 kg, your dose will be 120 mg. If you weigh 50 kg or more, your dose will be 160 mg. You’ll take this dose twice daily, about 12 hours apart.

Dosage for thyroid cancer

Retevmo is also approved for advanced or metastatic thyroid cancer that has a RET gene fusion and requires systemic (whole-body) therapy. For this purpose, the cancer either did not respond or stopped responding to radioactive iodine.

If your doctor prescribes Retevmo for your thyroid cancer, you’ll likely take the recommended dosage. If you weigh less than 50 kg, your dose will be 120 mg. If you weigh 50 kg or more, your dose will be 160 mg. You’ll take this dose twice daily, about 12 hours apart.

Dosage for medullary thyroid cancer

Doctors may prescribe Retevmo for advanced or metastatic medullary thyroid cancer (MTC) that requires systemic therapy. Retevmo is approved to treat MTCs with a certain change in the RET gene.

If your doctor prescribes Retevmo, you’ll likely take the recommended dosage for MTC. If you weigh less than 50 kg, your dose will be 120 mg. If you weigh 50 kg or more, your dose will be 160 mg. You’ll take this dose twice daily, about 12 hours apart.

Children’s dosage

Retevmo is approved to treat certain thyroid cancers with a RET gene fusion in children ages 12 years and older. The children’s dosage for thyroid cancer is the same as in adults. For details, see “Dosage for thyroid cancer” just above.

Talk with your child’s doctor if you have questions about their dosage for thyroid cancer.

Long-term treatment

Retevmo is meant to be a long-term treatment. If you and your doctor determine that Retevmo is safe and effective for you, you’ll likely take it long term.

Before you start taking Retevmo, your doctor will discuss your treatment plan with you.

The Retevmo dosage your doctor prescribes will depend on several factors. These include:

  • your body weight
  • how your body responds to Retevmo
  • other medications you take
  • side effects you may have with Retevmo
  • your liver function

Other medical conditions you have can also affect your Retevmo dosage.

Dosage adjustments

Your doctor may need to adjust your dosage if you take certain medications, such as CYP3A* inhibitors or inducers. These drugs can affect the level of Retevmo in your body. To find out what drugs may interact with Retevmo, see the “Interactions” section of this article.

Your doctor may also need to adjust your dosage if you have liver damage or if you experience certain side effects while taking Retevmo. To learn about Retevmo’s side effects, see this article.

Be sure to tell your doctor about all medications you take and any health conditions you may have.

* CYP3A is an enzyme (type of protein) in the liver that breaks down medications.

Retevmo comes as a capsule you swallow whole. Do not divide, crush, or chew the capsule or place it in water. You may take your dose with or without food.

You should take your Retevmo doses about 12 hours apart. It may be helpful to take Retevmo around the same times every day, such as morning and evening. This helps maintain a steady level of the drug in your body so Retevmo can work effectively.

If you take certain medications for heartburn or acid reflux, ask your doctor about taking Retevmo. In general, if you take:

  • a proton pump inhibitor such as Prilosec (omeprazole), be sure to take your Retevmo dose with a meal or snack
  • an H2 blocker such as Pepcid (famotidine), take your Retevmo dose 2 hours before or 10 hours after the H2 blocker
  • an antacid such as Tums (calcium carbonate), take your Retevmo dose 2 hours before or 2 hours after the antacid

If you have trouble swallowing capsules, see this article for tips on how to take this form of medication. You can also talk with your doctor or pharmacist.

If you have questions about how to take Retevmo, talk with your doctor or pharmacist. There’s also information about taking Retevmo on the manufacturer’s website.

ACCESSIBLE DRUG LABELS AND CONTAINERS

Some pharmacies offer labels with large print, braille, or a code you scan with a smartphone to convert text to speech. If your local pharmacy doesn’t have these options, your doctor or pharmacist might be able to recommend a pharmacy that does.

If you’re having trouble opening medication bottles, ask your pharmacist about putting Retevmo in an easy-open container. They also may recommend tools that can make it easier to open bottles.

If you miss a dose of Retevmo, take it as soon as you remember. If it’s within 6 hours of your next dose, skip the missed dose. Then take your next scheduled dose at your regular time. Do not take two doses to make up for the missed one. If you’re not sure whether you should take a missed dose or skip it, talk with your doctor or pharmacist.

To help make sure that you don’t miss a dose, try using a medication reminder. This can include setting an alarm or putting a note where you’ll see it, such as on your bathroom mirror or bedside table. You could also download a reminder app on your phone.

It’s important that you do not take more Retevmo than your doctor prescribes. For some medications, taking more than the recommended amount may lead to harmful effects or overdose.

If you take more than the recommended amount of Retevmo

Call your doctor right away if you believe you’ve taken too much Retevmo. Another option is to call America’s Poison Centers at 800-222-1222 or use its online tool. If you have severe symptoms, immediately call 911 or your local emergency number, or go to the nearest emergency room.

Below are some frequently asked questions about Retevmo.

How long does it take for Retevmo to start working?

Retevmo starts to work after your first dose. Because of how the drug works, you likely won’t feel the drug working in your body. But your doctor will monitor you during treatment to check whether the drug is working to treat your condition.

Talk with your doctor if you have questions about what to expect with Retevmo treatment.

Is there a typical dosage range for Retevmo?

Yes, the typically recommended dosage range for Retevmo is based on your body weight. If you weigh less than 50 kg (less than about 110 lb), your dose will be 120 mg. If you weigh 50 kg or more, your dose will be 160 mg. You’ll take this dose twice daily.

For more information about Retevmo dosages, see the “Retevmo dosage” section above. You can also talk with your doctor or pharmacist.

The dosages in this article are typical dosages provided by the drug’s manufacturer. If your doctor recommends Retevmo for you, they’ll prescribe the dosage that’s right for you. Always follow the dosage that your doctor prescribes.

As with any drug, never change your dosage of Retevmo without your doctor’s recommendation. If you have questions about the dosage of Retevmo that’s best for you, talk with your doctor.

Besides learning about dosage, you may want other information about Retevmo. These additional articles might be helpful:

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.