Larotinib/Larotinib usage and dosage

Larotrectinib/Larotrectinib is a drug designed to treat solid tumors and is suitable for adult and pediatric patients. These patients may carry neurotrophic receptor tyrosine kinase (NTRK) gene fusions without known resistance mutations, or may be at risk of tumor metastasis or serious deterioration of their condition after surgical resection, and other treatments cannot meet their needs or their condition still progresses after treatment.

Larotrectinib is available in capsule and oral solution forms, which can be used interchangeably. Patients selected for larotrectinib are based on the detection of NTRK gene fusions in tumor samples. Currently, there is no FDA-approved specific NTRK gene fusion detection method.

1. Medication guidance:

Standard dosage: For adults and children with a body surface area of ≥1.0 square meters, it is recommended to take 100 mg orally twice a day.

Adults and children with a body surface area <It is recommended to take 100mg/m2 orally twice a day according to the body surface area, with or without food, until the disease progresses or unacceptable toxic reactions occur.

2. Dosage adjustment:

If adverse reactions occur, the doctor will adjust the dose according to the situation. For example, it can be reduced to twice a day for the first time75mg (or 75mg/m2). Subsequently, it can be further adjusted to 50 mg twice a day (or 50 mg/m2), and then to 100 mg once a day (or 25 mg/m2 twice a day). If it is still intolerable after three adjustments, larotrectinib should be permanently discontinued. If the adverse reactions are not relieved within 4 weeks, permanent discontinuation is required.

3. Drug interactions:

Avoid coadministration with strongCYP3A4 inhibitors; if this cannot be avoided, the dose of larotrectinib needs to be reduced by 50%. After stopping the inhibitor, the original dose needs to be restored. Avoid coadministration with strong CYP3A4 inducers; if avoidance is unavoidable, double the dose of larotrectinib. After stopping the inducer, the original dose needs to be restored. In patients with moderate to severe hepatic impairment, the starting dose needs to be reduced by 50%.

4. Medication method:

Capsules should be swallowed whole with water and should not be chewed or crushed.

If the missed dose is within 6 hours of the next scheduled dose, no refill is required.

If you vomit after taking the capsule, there is no need to take another dose. Just take the next dose at the scheduled time.

When using oral solutions, measure accurately with a special measuring device and do not use a household teaspoon.

When taking medicine for children, the medicine should be injected into the inside of the mouth and kept upright for a few minutes after taking the medicine to prevent spitting. Do not give the medicine again if you spit it out or if you are not sure whether it has been taken completely.