How It Works
Methotrexate, sometimes called MTX, reduces inflammation caused by juvenile idiopathic arthritis (JIA).
Why It Is Used
Most experts believe the potential benefits of methotrexate in children with JIA are greater than the risks of serious side effects, and methotrexate has become the preferred second-line medicine for children with JIA. It is generally reserved for children who do not respond to nonsteroidal anti-inflammatory drugs (NSAIDs). But some children who have JIA, especially those with polyarticular and extended oligoarticular JIA, gain significant benefit from early methotrexate treatment. Methotrexate reduces symptoms and may slow joint damage.
Methotrexate may also be used for resistant chronic inflammatory eye disease (uveitis) in children with JIA.
How Well It Works
Methotrexate appears to be effective for juvenile idiopathic arthritis.1 Methotrexate may:
Serious but rare side effects of methotrexate include:
- Low blood counts.
- Inflammation of the lungs (allergic pneumonitis).
Liver inflammation (abnormal liver enzyme blood tests or hepatitis) or mild to moderate scarring (fibrosis). Liver inflammation or fibrosis seems to be less common and less severe in children than in adults.
- Severe liver damage (severe scarring or cirrhosis). Cirrhosis is not reversible, but it is rare and is most often seen in patients with liver disease, diabetes, or alcohol abuse.
Minor side effects include:
None of these side effects are permanent. Folic acid supplements may decrease the severity of side effects.
Effects on blood cells and liver inflammation can be detected early by regular blood tests (every 1 to 2 months) and almost always return to normal when methotrexate is discontinued. Regular blood tests may help detect liver inflammation. In very rare cases, inflammation can lead to more serious liver scarring (fibrosis or cirrhosis).
Anyone taking methotrexate must avoid alcohol use to prevent significant drug interactions.
Women taking methotrexate should avoid becoming pregnant, as the drug causes miscarriage and possibly birth defects.
See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)
What To Think About
Children who are taking methotrexate should not take other medicines without the approval of the doctor who is treating their JIA. Methotrexate interacts dangerously with certain other medicines. Methotrexate should not be used in children who have chronic liver disease. Some children with kidney disease can take methotrexate, but they require an adjusted dose and careful monitoring.
Frequent blood monitoring for blood cell counts and liver function enzymes should be done during methotrexate therapy.
Methotrexate may increase the risk for certain infections, such as shingles and pneumonia.
Methotrexate has been shown to be safe for long-term use in most children, but it is still usually tapered off and stopped about 1 year after remission.2
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Nistala K, et al. (2009). Juvenile idiopathic arthritis. In GS Firestein et al., eds., Kelley's Textbook of Rheumatology, 8th ed., vol. 2, pp. 1657-1675. Philadelphia: Saunders Elsevier.
Giannini EH, Brunner HI (2005). Treatment of juvenile rheumatoid arthritis. In WJ Koopman, LW Moreland, eds., Arthritis and Allied Conditions, 15th ed., vol. 1, pp. 1301-1318. Philadelphia: Lippincott Williams and Wilkins.
Primary Medical ReviewerSusan C. Kim, MD - Pediatrics
Specialist Medical ReviewerJohn Pope, MD - Pediatrics
Current as ofSeptember 9, 2014