Rheumatoid arthritis (RA) is an autoimmune disease that causes joint destruction and greatly reduces a patient's QOL (quality of life). The clinical response and safety in many clinical trials in RA patients using biological medication have been reported. However, there are few reports on the influence of concomitant drugs on patients using biological medication. We investigated the change in the concomitant drug with the start of biological medication (etanercept, tocilizumab, abatacept, adalimumab, infliximab) and the concomitant drug for 12 months. We found a difference with each biological in terms of age, average methotrexate dose, steroid dose, and non-steroidal anti-inflammatory drug. Furthermore, as a result of investigating the change in the concomitant drug for 12 months, the average methotrexate dose did not change except for that of tocilizumab. However, the average steroid dose and non-steroidal anti-inflammatory drug decreased or stopped. It was shown that biological medication may influence not only a good clinical response but a concomitant drug.
