Natalizumab adverse events are rare in patients with multiple sclerosis

Objective To assess the prevalence and the profile of adverse events (AE) of natalizumab in patients with multiple sclerosis (MS). Methods Data collection from neurologists attending to patients with MS at specialized units in Brazil. Results Data from 103 patients attending the infusion centers of 16 MS units in 9 Brazilian states were included in the study. The total number of infusions was 1,042. Seventy-nine patients (76.7%) did not present any AE. Twenty-four patients (23.3%) presented only mild AE. There were three major AE, including two deaths. These three occurrences, although not necessarily being drug-related, must be taken into consideration. Conclusion The profile of AEs for natalizumab shows that 97% of patients have none or only mild AE. However, still due to safety worries, the use of this medication should be restricted to MS units under the care of specialized neurologists.