If the increase in liver blood tests is persistent, progressive or very high, the medication should be stopped. Liver blood tests are usually done every 4 to 8 weeks. They sometimes can be minimized by taking the methotrexate with food. Mouth sores also can occur due to methotrexate. They tend to be painful, like canker sores.
Diarrhea is infrequent but like mouth sores can be serious.
Although feeling faint or appearing pale may be a clue to anemia, often anemia is present without symptoms. Regular blood testing is necessary. Many rheumatologists recommend a complete blood count every 4 to 8 weeks. Even so, decreased blood counts can occur between blood tests. Thus, any person experiencing symptoms of decreased blood counts should stop the methotrexate and consult a physician immediately.