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Drug Interactions between larotrectinib and methadone

This report displays the potential drug interactions for the following 2 drugs:

  • larotrectinib
  • methadone

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Interactions between your drugs


methadone larotrectinib

Applies to: methadone and larotrectinib

Consumer information for this interaction is not currently available.

MONITOR: Coadministration with larotrectinib may increase the plasma concentrations of drugs that are substrates of the CYP450 3A4 isoenzyme. In study subjects, coadministration of midazolam, a sensitive CYP450 3A4 substrate, with larotrectinib 100 mg twice daily increased midazolam peak plasma concentration (Cmax) and systemic exposure (AUC) by 1.7-fold each compared to administration of midazolam alone. The Cmax and AUC of 1-hydroxymidazolam, the main metabolite of midazolam, were both increased by 1.4-fold.

MANAGEMENT: Caution is advised when larotrectinib is used concomitantly with drugs that are substrates of CYP450 3A4, particularly those with a narrow therapeutic range. Dosage adjustments as well as clinical and laboratory monitoring may be appropriate for some drugs whenever larotrectinib is added to or withdrawn from therapy. Patients should be monitored for the development of adverse effects. Some authorities recommend avoiding concomitant use of larotrectinib and sensitive CYP450 3A4 substrates or substrates with narrow therapeutic ranges. These drugs include, but are not limited to: alfentanil, cisapride, colchicine, cyclosporine, fentanyl, ivacaftor, lovastatin, simvastatin, oral midazolam, triazolam, pimozide, quinidine, sildenafil, ergot derivatives, macrolide immunosuppressants, and vinca alkaloids.


  1. "Product Information. Vitrakvi (larotrectinib)." Bayer Pharmaceutical Inc, West Haven, CT.
  2. Cerner Multum, Inc. "Australian Product Information." O 0
  3. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

Drug and food interactions


methadone food

Applies to: methadone

Grapefruit juice can increase the blood levels and effects of methadone. If you regularly consume grapefruits or grapefruit juice, you should be monitored for side effects and/or changes in methadone levels. Do not increase or decrease the amount of grapefruit products in your diet without first talking to your doctor. Orange juice is not expected to interact.

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larotrectinib food

Applies to: larotrectinib

Grapefruit juice can increase the blood levels of larotrectinib. This may increase the risk and/or severity of side effects such as dizziness, confusion, coordination problems, memory problems, liver problems, and tingling, numbness or burning in the hands and feet. You should avoid the consumption of grapefruit and grapefruit juice during treatment with larotrectinib. Talk to your doctor or pharmacist if you have questions on this or other medications you are prescribed. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

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Therapeutic duplication warnings

No warnings were found for your selected drugs.

Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.