Comprehensive research highlights side effects tied to long-used anti-rheumatic drug

Patients who take methotrexate to treat autoimmune diseases like rheumatoid arthritis or psoriasis have a modest, but increased risk of certain cancers, infections, gastrointestinal, lung and blood problems.

While the findings published in the journal Annals of Internal Medicine do not suggest that patients need to quit taking methotrexate if it benefits them, researchers say it could help doctors better balance the risk and benefits of the age-old drug.

Researchers analyzed data from 4,800 participants of the NHLBI-funded Cardiovascular Inflammation Reduction Trial (CIRT), who were randomized to take a placebo or low-dose methotrexate combined with folate. Of the nearly 2,400 participants who took methotrexate, 87 percent had notable side effects compared to 81.5% of those who took a placebo.

Participants who took methotrexate were twice as likely to develop skin cancer compared to those who took a placebo. Researchers also found an increase in liver test abnormalities and five cases of cirrhosis among participants who took methotrexate. NHLBI funded this study.