Objectives: Six cases of pancytopenia were analyzed retrospectively among 350 patients with rheumatoid arthritis treated with methotrexate. Pancytopenia is an uncommon but severe secondary effect of methotrexate.
Case reports: Five patients were hospitalized for infectious complications or hemorrhage with favorable outcome. One patient died due to septic shock. There were risk factors in all 6 patients: 5 were over 65 years of age, creatinine clearance was under 50 ml/min in 4, hypoalbuminemia was found in 4 and methotrexate was combined with an antiinflammatory drug in 4 and with ranitidine in 2. The pharmacological imputability of methotrexate was probable in 4 of the 6 patients.
Discussion: Acute pancytopenia in patients treated with methotrexate can be prevented by recognizing risk factors, regular laboratory tests and supplementation of all patients with folic acid according to protocols to be established.