Peri-Infusional Adverse Reactions to Rituximab in Mexican Patients with Rheumatoid Arthritis

Abstract

Background. The treatment of rheumatoid arthritis (RA) has significantly improved since the introduction of biologics like rituximab. Rituximab achieves selective B lymphocyte depletion and, thereby, reduce inflammation. It has adverse reactions related to the immunogenic response. Objective. The aim of this study was to evaluate the frequency and severity of rituximab adverse reactions in Mexican patients with RA. Methods. A prospective, observational, descriptive, open-labeled, multicenter cohort study of intensive pharmacovigilance was conducted during 17 months in 10 hospitals. We included 335 adult patients with RA, 26 male an 309 female. They received two doses of rituximab (1000 mg) on days 1 and 15 in combination with methotrexate. Adverse reactions were graded according to the National Cancer Institute (NCI) scale and causality was established with the Naranjo algorithm. Infusions were classified as fast (0 to 180 minutes) and slow (> 181 minutes). The first and second infusions were compared. Results. The total number of infusion episodes recorded was 631 and 36 adverse reactions were informed in 24 patients (7.1 %). There were no differences between the variances of the first and second infusions. All the adverse reactions were considered mild to moderate (NCI Scale). According to Naranjo algorithm, the adverse reactions to rituximab were possible or probable. The infusion speed did not have an influence on the adverse reactions; whereas the incident rate was lower than that reported by other authors. Conclusions. Rituximab has a favorable safety profile in Mexican patients.