Surveillance of adverse drug events associated with etanercept prescribed for juvenile idiopathic arthritis in a single center up to 9-years: A retrospective observational study

The introduction of biologic agents opened a new era of treatment of juvenile idiopathic arthritis (JIA) over the past decade. From clinical experience, it appears that biological agents are well tolerated overall, and serious adverse events are rare. However, such clinical studies have not been conducted in Korea. Therefore, we examined the safety profile of JIA patients with biologics in a single center in Korea. All JIA outpatients treated from April 2004 to June 2013 were enrolled and retrospectively reviewed. Pharmacy-based surveillance of adverse drug events (ADEs) was identified by recording the patient's symptoms in the medical record and suspected ADEs were additionally explored by screening laboratory test values and observing changes in medication orders. Finally, 83 patients were enrolled and experienced 109 ADEs in 52 patients. Most ADEs (99.1%) were mild to moderate in severity assessment. The total follow-up time was 328 patient-treatment years and the overall rate of ADEs was 0.33 per patient-years for etanercept. Infection including upper respiratory tract was the most common ADE and concomitant corticosteroids contributed to the risk of infections. If the dose of prednisolone increases 0.34 mg/kg/day, the probability of developing infections increases 3.29 times. Also, all 11 patients who stopped etanercept with injection site reactions were receiving a single use prefilled syringe. In our study, etanercept appears well tolerated and safe. Children affected by JIA should be carefully monitoring so as to limit the risk of ADEs during etanercept as much as possible. To gain further knowledge about risk profiles, national collaboration for the accumulation of long-term data should be encouraged in Korea.