Methotrexate/Asparaginase Interactions

This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.

Medical warning:

Serious. These medicines may interact and cause very harmful effects. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.

How the interaction occurs:

The cause of the interaction is not known. The effect of methotrexate may decrease.

What might happen:

The methotrexate therapy may not be effective when given after asparaginase. This is not a problem if the asparaginase is given after methotrexate therapy.

What you should do about this interaction:

Your healthcare professionals (e.g. doctor or pharmacist) may already be aware of this drug interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.

  • 1.Capizzi RL. Asparaginase-methotrexate in combination chemotherapy: schedule- dependent differential effects on normal versus neoplastic cells. Cancer Treat Rep 1981;65 Suppl 4:115-21.
  • 2.Elspar (asparaginase) US prescribing information. Merck & Co., Inc. July, 2006.

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CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.