Injectable Methotrexate — by Mouth

Q:  I have heard that it is possible to take injectable methtrexate by mouth and that it costs less than taking oral methotrexate. Is this correct? If so, how can my doctor determine the best dosage of injectable methotrexate?

A:  You heard right. One dose of injectable methotrexate costs about one-third as much as the same dose of generic methotrexate tablets. This pricing difference may be due to the fact that injectable methotrexate is often used in high doses for cancer patients, so the unit cost is lower in the injectable form. The dose ranges of injectable and oral methotrexate for arthritis are the same, so your doctor would probably switch you to the same dose as your injection, then monitor your response as usual. If you switch from a tablet to an injectable form of methotrexate, you may want to have your pharmacy draw up the correct dose into a syringe ahead of time. When the time comes to take the medication, you would squirt it into an eight-ounce glass of water and drink it. Alternatively, you may ask your pharmacist about a specially formulated syrup to help dilute the medication. Of course, you should talk to your physician about the best way to take methotrexate. If taking the drug orally causes you stomach upset, the best way to take injectable metho-trexate is the way in which it was intended — by injection.

DONALD R. MILLER, PharmD Pharmacist