Adverse drug reactions of Rituximab in patients suffering from autoimmune neurological diseases

Background Rituximab, a chimeric human/mouse monoclonal antibody targeting CD-20 antigens, has been used recently for various rheumatological and autoimmune diseases, including autoimmune neurological disorders. Objectives We aimed to study the frequency, seriousness, causality, and preventability of adverse drug reactions (ADRs) of rituximab in Iranian patients with autoimmune neurological diseases. Methods In this cross-sectional observational study, patients with autoimmune neurological diseases who had an indication for rituximab treatment were enrolled. Naranjo adverse drug reaction probability scale was used to assess the causality of ADRs, and the preventability of the ADRs was determined by P-Method. The seriousness of ADRs was also determined. Results A total of 264 ADRs were recorded from 97 patients. The Median (min-max) number of ADRs experienced by patients was 3 (1-7) events. 11.3% of patients experienced serious ADRs. 18.2% and 26.9% of ADRs were Definite and Probable, respectively. Only 5% of the ADRs were "preventable". The most frequent ADRs were rituximab infusion-related reactions. Conclusion Rituximab had an acceptable safety profile in our study patients. However, there must be certain cautions regarding the use of the medication for the elderly or patients with a compromised immune system. Timely detection and management of ADRs would also be crucial to prevent severe and permanent damages. Moreover, considering that rituximab is used as an off-label treatment for autoimmune neurological diseases, a risk-benefit assessment would be necessary before deciding on the treatment choice.