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Targeted Therapy

Brand names:


Other names:

Larotrectinib Sulfate; LOXO-101; TRK Inhibitor LOXO-101

Often used for:

Solid tumors

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What is Larotrectinib?

Larotrectinib (VitrakviÒ) is a type of medicine called a targeted therapy. This medicine is a tropomysin receptor kinase (TRK) inhibitor. It acts to block certain cell signals that may help keep cancer cells from growing. Larotrectinib is used to treat some solid tumors.

Patients will have regular blood draws to check blood counts and to monitor liver and kidney function.


May be given as a capsule by mouth


May be given as a liquid by mouth

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Possible Side Effects

  • Weight gain
  • Bone fracture
  • Cough
  • Trouble sleeping
  • Nausea or vomiting
  • Diarrhea
  • Constipation
  • Fatigue or weakness
  • Dizziness
  • Headache
  • Loss of appetite
  • Stuffy nose
  • Joint or muscle, or back pain
  • Pain in the arms or legs
  • Muscle weakness
  • Low blood counts (may cause increased risk of infection, bleeding, anemia and/or fatigue)
  • Skin rash
  • Acne
  • Dry skin, itching
  • Swelling

Not all patients who take larotrectinib will experience these side effects. Common side effects are in bold, but there may be others. Please report all suspected side effects to your doctor or pharmacist.

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Tips for Families

Be sure to discuss these and other recommendations with your doctor or pharmacist.

  • The care team may recommend medicines or foods to help manage diarrhea. Anti-nausea medicines may also be prescribed.
  • While taking this medicine, avoid foods or beverages containing grapefruit or grapefruit juice.
  • Patients should tell their doctor if they are pregnant or breastfeeding. This medicine may cause harm to an unborn baby if taken during pregnancy. Patients should not breast feed a baby while taking this medicine.
  • Sexually active patients should take steps to prevent pregnancy during treatment and for 1 week after completing therapy. Female patients should take steps to prevent pregnancy during treatment and for 1 week after the last dose. Male patients should use a condom during treatment and for 1 week after the last dose.
  • This medicine can increase the risk of a broken bone.

Larotrectinib at home:

  • Take larotrectinib at the same time each day, with or without food. It is usually given 2 times per day, 12 hours apart.
  • Capsules: Swallow capsules whole. Do not crush, chew, or break. Store at room temperature in a dry place.
  • Liquid medicine: Measure carefully. Use the measuring device that comes with the medicine. Store in the refrigerator.
  • Give a missed dose as soon as possible. If it is within 6 hours of the time for the next dose, skip the dose. Do not give 2 doses at the same time.
  • If the patient vomits after taking larotrectinib, do not give another dose.
  • Store at room temperature.
  • Do not use the medicine past the expiration date.
  • Follow instructions for safe handling and disposal.

Always check the medication label. Many medicines look the same. Do not take any new medicine, including over-the counter medicines or supplements, without checking with your doctor or pharmacist. Talk to your doctor or pharmacist about what to do in the case of a missed dose, allergic reaction, or medical emergency. This information is not intended to be a complete guide and is not a substitute for talking with your provider.