If arthritic Methotrexa fear ...

Updated 30 June 2014.

Written and reviewed by a Board Certified physician. See the Medical Review Board About.com.

Some patients with rheumatoid arthritis were alarmed when methotrexate was prescribed. The drug is known to be a chemotherapy drug used to treat cancer be. But it is right to classify or consider a chemotherapy drug methotrexate in rheumatoid arthritis prescribed? Maybe seems a topic that absolutely anything, but when a misunderstanding caused unnecessary fear or caution in patients with a drug that can help them, the question is not really important. Consider the facts.

The short answer

There are more than 50 years, methotrexate has been touted as a cure for cancer because of its anti-proliferative effect. In the last 25 years, the drug was widely considered anti-rheumatic diseases (FAME) to treat rheumatoid arthritis and other rheumatic diseases. Methotrexate actually considered a standard treatment and the drug of choice in the treatment of rheumatoid arthritis.

After a chapter in the book DMARDs, rheumatoid arthritis: early diagnosis and treatment, "His popularity is due to the ease of use (subcutaneously or orally once weekly dosing) based toxicities are well defined, the rapid onset of clinical benefit (usually within 6-8 weeks), long life, low cost, additive benefit when combined with other treatments DMARDs, and its ability to radiological lesions retard. "

How does methotrexate

This is supposedly toxicities with the inhibition of dihydrofolate reductase and folate associated production. When used as background therapy, however, seem related a known anti-inflammatory mediator adenosine induction methotrexate benefits. To improve the effect of methotrexate on the production of folic acid, a folic acid supplement daily is the usual pattern for patients with rheumatic diseases.

When used as a chemotherapeutic agent, to prevent cells with folic acid, methotrexate, DNA and RNA, which are at slowing the growth of cancer cells.

Reduce the need for primary therapy

When used as a chemotherapeutic agent methotrexate administered in a moderate to high doses. The dose is determined by the size of the patient, wherein the cancer treated and kidney function. Greater than or equal to 500 mg / m 2 dose is as high, with doses of 50 to 500 mg / m 2 are intermediate. Low dose will be less than 50 mg / m2.

If methotrexate for the treatment of rheumatoid arthritis, the dose is estimated to be low - usually 7.5 to 10 mg / week. If necessary, the dose may be escalated to a maximum of 25 mg / week.

If side effects or toxicity develops, it is estimated that reducing the dose or switch to oral methotrexate injection can treat questions. Routine blood tests are also in patients to detect early methotrexate (complete blood count, liver and renal profiles) problems so that adjustments can be made to be performed. While rare serious side effects develop, discontinuation of methotrexate therapy is necessary.

The Bottom Line

When he was asked by a comment if methotrexate is to be feared, because it is used as chemotherapy, rheumatologist Scott J. Zashin, MD (www.scottzashinmd.com/) replied: "Although methotrexate High doses can for chemotherapy, rheumatologists used be with methotrexate due to its low anti-inflammatory doses. not uncommon for a pharmacist to make a possible drug interaction between NSAIDs (a common treatment for rheumatoid arthritis) and methotrexate, but not seen as clinically significant interaction with the low dose of drug, the for the treatment of rheumatoid arthritis. Patients should not forget, also, that the drug is prescribed only met once a week in order to minimize possible side effects. "

_Sources:

_{Rheumatoid Arthritis: Early Diagnosis and Treatment. Kush, Grape Leaf and Kavanaugh. Third Edition. Chapter 11 - antirheumatic disease.}

_{Toxicity and therapeutic use of high-dose methotrexate. Ann S. LaCasce, MD. Al Dia. Revised November 2013.
http://www.uptodate.com/contents/therapeutic Terms and methotrexate toxicity-of-high-dose}

_{Methotrexate. American Cancer Society. 12/29/2011.
http://www.cancer.org/treatment/treatmentsandsideeffects/guidetocancerdrugs/methotrexate}