Larotrectinib

Say it: lair-oh-TREK-tih-nib · Brand names: Vitrakvi

Larotrectinib is a targeted therapy that blocks abnormal proteins made by cancers with an NTRK gene change.

What it is

Some cancers have a gene change called an NTRK fusion. This change makes a protein that keeps telling the cancer cells to grow. Larotrectinib blocks that protein and can shrink the cancer, no matter where in the body it started.

Often used for

• solid tumors with an NTRK gene change, in adults and children

How you get it

Larotrectinib is taken by mouth at home, twice a day, with or without food. It comes as capsules and as a liquid. Your schedule may be different.

Common side effects and what helps

• Feeling tired or weak. Rest when you need to, and try short walks.
• Feeling sick to your stomach or throwing up. Eat small meals and ask your team about anti-nausea medicine.
• Feeling dizzy. Stand up slowly and be careful when driving.
• Cough. Tell your team if it is new or gets worse.
• Constipation. Drink fluids, eat fiber, and ask your team about a stool softener.
• Diarrhea. Drink plenty of fluids. Tell your team early, since they may give you medicine to help.
• Muscle or bone aches. Gentle movement and rest may help.
• Changes in liver blood tests. Your team will check these.

Call your care team right away if you have

• Confusion, memory problems, trouble speaking, mood changes, or very bad dizziness
• Trouble walking or keeping your balance
• Bone pain or a broken bone
• Yellow skin or eyes, dark tea colored urine, or pain on the right side of your belly
• A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher, or chills

Before you start, tell your team

• If you are pregnant, may become pregnant, or are breastfeeding
• If you have liver problems
• If you have any nervous system problems
• All the medicines, vitamins, and herbal products you take, since some can change how this medicine works

Good to know

• It can affect the brain and nerves, causing dizziness, confusion, mood changes, or sleep problems. Do not drive until you know how it affects you.
• You will have blood tests to check your liver, every 2 weeks at first.
• It can raise the chance of broken bones.
• This medicine can harm an unborn baby. Use birth control during treatment and for some time after. Ask your team how long.

At home

• Take it at about the same times each day. Swallow capsules whole with water.
• If you take the liquid, use the oral syringe from the pharmacy to measure it. Keep the liquid in the refrigerator.
• Do not eat grapefruit or drink grapefruit juice while taking this medicine.
• If you miss a dose or throw up after taking it, ask your team what to do. Do not take extra pills to make up for it.
• Store capsules at room temperature, away from children and pets.

Questions to ask

• How long will I take this medicine?
• Is it safe for me to drive?
• How will we know if this medicine is working?
• Which side effects should I call about right away, and which can wait until my next visit?

Side effect guides

• Fatigue (tiredness)
• Nausea and vomiting
• Diarrhea
• Constipation
• Cough

Last updated: 2026-10-27. Medically reviewed by Veli Bakalov, MD, medical oncologist (October 2026). General education from Step by Step, the patient portal of HemeOncBuddy.