Methotrexate (Rheumatrex, Trexall) is an effective treatment which can be used safely by most patients, with appropriate precautions. Nausea, diarrhea, mouth sores, and hair loss may occur but are very uncommon at the low doses used to treat rheumatoid arthritis. These side effects are reversible when the medication is stopped. Mild elevation of liver enzymes occurs commonly. A decrease in blood-cell counts may occur but is uncommon in rheumatoid doses. Regular monitoring of liver function and blood counts is recommended every two to three months. If abnormalities develop, they typically will resolve with a reduction in dosage of methotrexate or by stopping the drug altogether.