Serious Side Effects That May Occur with Larotrectinib

Serious Side Effects That May Occur with Larotrectinib

Larotrectinib may cause several serious side effects that require close attention from patients and caregivers. First, central nervous system problems can occur, including dizziness, confusion, difficulty concentrating, attention and memory impairment, mood changes, and sleep disturbances. If these symptoms appear or worsen, you should inform your doctor immediately. Second, fractures may occur while taking larotrectinib. Patients should also report any pain, changes in mobility, or bone abnormalities promptly. Additionally, liver problems are relatively common; blood tests may show abnormal liver function, which can sometimes become serious. Your doctor will monitor your liver function before and during treatment as needed.

Liver Problems and Other Common Side Effects

Specific symptoms of liver problems include yellowing of the skin or the whites of the eyes, dark or brown urine, pain in the upper right abdomen, bruising or bleeding more easily than usual, fatigue, nausea and vomiting, and loss of appetite. If any of these new or worsening symptoms occur, you must contact your healthcare provider immediately. In addition to serious side effects, the most common side effects of larotrectinib include: elevated levels of certain liver function tests, decreased red and white blood cell counts, decreased blood albumin levels, muscle and bone pain, elevated alkaline phosphatase levels, decreased blood calcium levels, fatigue, vomiting, cough, constipation, fever, diarrhea, nausea, abdominal pain, dizziness, and rash. If serious side effects occur, your doctor may reduce your dose, temporarily stop treatment, or permanently discontinue therapy.

Use in Special Populations and Effects on Fertility

Before taking larotrectinib, be sure to tell your doctor about all of your medical conditions, especially if you have liver problems or neurological disorders. Larotrectinib may cause harm to an unborn baby, so women who are pregnant or planning to become pregnant need to be particularly cautious. Females with reproductive potential should have a pregnancy test before treatment and use effective contraception during treatment and for 1 week after the last dose. Males with female partners of reproductive potential should also use effective contraception during the same period. It is not known whether larotrectinib passes into breast milk, so do not breastfeed during treatment and for 1 week after the last dose. In addition, larotrectinib may affect female fertility; talk to your doctor if you have concerns. While taking this medication, avoid driving or operating machinery until you know how the drug affects you, and avoid taking St. John’s wort, eating grapefruit, or drinking grapefruit juice.