Vitrakvi (larotrectinib) is a brand-name drug prescribed for certain kinds of solid tumors in adults and children. It comes as an oral capsule or solution that’s typically taken twice per day. The dosage can vary depending on the condition the drug is used to treat.

Vitrakvi is approved by the Food and Drug Administration (FDA) for use in adults and children with solid tumors that:

  • have a gene fusion known as neurotrophic receptor tyrosine kinase (NTRK)
  • have spread to other parts of the body and cannot be removed with surgery
  • have no other treatment options or have gotten worse after treatment

Vitrakvi belongs to a drug class called kinase inhibitors. Vitrakvi is not available in a generic version.

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

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

Below is information about Vitrakvi’s forms, strengths, and dosages.

Vitrakvi forms

Vitrakvi comes as an oral capsule and an oral solution.

Vitrakvi strengths

Vitrakvi oral capsules come in two strengths: 25 milligrams (mg) and 100 mg.

Vitrakvi oral solution comes in a 50-milliliter (mL) or 100-mL bottle. The strength of the solution is 20 mg/mL.

Typical dosages

The following information describes dosages that are commonly prescribed or recommended. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs.

Dosage for solid tumors

Doctors may prescribe Vitrakvi to treat solid tumors.

If your doctor prescribes Vitrakvi for you, your dose will be 100 mg, taken twice per day. You’ll continue this dosage as long as Vitrakvi is working for your condition and does not cause serious side effects.

For more information about your specific dosage, talk with your doctor.

Children’s dosage

Vitrakvi is approved to treat solid tumors in children ages 1 month and older.

If your doctor prescribes Vitrakvi for your child, the dose will be based on their body surface area (BSA), measured in square meters (m2).

If your child’s BSA is 1 m2 or more, they’ll typically receive the adult dosage: 100 mg twice per day.

If their BSA is less than 1 m2, their dose will be 100 mg per m2 (mg/m2). They’ll take this dose twice per day. They’ll continue this dosage as long as Vitrakvi is working for their condition and does not cause serious side effects.

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

Long-term treatment

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

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

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

  • your age
  • your body weight and body surface area
  • the form of Vitrakvi you take
  • other medications you take
  • side effects you may have with Vitrakvi
  • your liver function

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

Dosage adjustments

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

Your doctor may also need to adjust your dosage if you have liver damage.

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

* A liver enzyme is a type of protein in the liver that breaks down medications.

Vitrakvi comes as an oral capsule and an oral solution that you swallow. If your doctor prescribes the capsules, do not divide, crush, chew, or place them in water. If your doctor prescribes the oral solution, they’ll show you how to measure your dose correctly.

You may take your dose with or without food.

It may be helpful to take Vitrakvi doses around the same time of day. This helps maintain a steady level of the drug in your body so Vitrakvi can work effectively.

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 use Vitrakvi oral solution, talk with your doctor or pharmacist. There are also step-by-step instructions on the manufacturer’s website.


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 Vitrakvi in an easy-open container. They also may recommend tools that can make it easier to open bottles.

If you miss a dose of Vitrakvi, take it as soon as you remember. If your next dose is due within 6 hours, skip the missed dose and take your next scheduled dose.

If you vomit after taking a dose, wait and take your next scheduled dose. Do not take two doses to make up for the missed one. Talk with your doctor or pharmacist if you’re unsure whether to take a missed dose or skip it.

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 don’t take more Vitrakvi 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 Vitrakvi

Call your doctor right away if you believe you’ve taken too much Vitrakvi. 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, call your local emergency number, or go to the nearest emergency room.

Below are some frequently asked questions about Vitrakvi.

Is the dosage of Vitrakvi similar to the dosage of Keytruda?

No, not really. Although both drugs may be prescribed to treat certain types of tumors, the forms and how often you receive them are different.

Vitrakvi comes as an oral capsule or oral solution that you take twice per day. Pembrolizumab (Keytruda) comes as an intravenous (IV) infusion that a healthcare professional gives. It’s dosage schedule varies based on the type of cancer being treated.

The dose in milligrams for each drug also differs because they have different active ingredients. Your doctor will prescribe the drug and the dosage that’s right for you.

To learn more about how these drugs compare, talk with your doctor.

How long does it take for Vitrakvi to start working?

Although Vitrakvi starts working after your first dose, it may take weeks or months to see the full effect of the drug. How long it takes to work also depends on the condition it is treating. 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 Vitrakvi treatment.

The dosages in this article are typical dosages provided by the drug’s manufacturer. If your doctor recommends Vitrakvi for you, they will 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 Vitrakvi without your doctor’s recommendation. If you have questions about the dosage of Vitrakvi that’s best for you, talk with your doctor.

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

  • More about Vitrakvi: For information about other aspects of Vitrakvi, refer to this article.
  • Details about solid tumors: For details about these conditions, see our cancer hub.

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.