Objective: To investigate the safety of infliximab (INF) combination therapy with leflunomide (LEF) or azathioprine (AZA) in patients with rheumatoid arthritis (RA).
Method: A standardized questionnaire on the use of INF in combination with LEF or AZA was mailed to hospital physicians and collected over a 2 month period. Adverse events (AE) and the reasons for withdrawal of combination therapy were analyzed.
Results: Data on 225 patients with RA were collected retrospectively. INF was used in combination with LEF in 171 patients and with AZA in 54. The duration of INF exposure was similar in both groups (mean 8.8 mo). AE were reported in 75 patients (33.3%), 60 LEF/INF (35%) and 15 AZA/INF combinations (27.8%) (p=nonsignificant). No unexpected AE were observed. The main AE were infections (6.2%), cytopenia (5.8%), hepatotoxicity (5.8%), reactions to infusion (5.3%), and skin reactions (4%). At the time the questionnaires were sent out, 161 patients were continuing combination therapies. The main reasons for drug withdrawal were AE (53 patients, 23.5%), inefficacy (10 patients, 4%), and one temporary discontinuation for surgery.
Conclusion: Our study suggests that INF used in combination with LEF or AZA could be an alternative to methotrexate/INF combinations.