Post-infusion observation of patients with multiple sclerosis receiving natalizumab: Is it necessary?

Natalizumab (Tysabri ®), the first monoclonal antibody approved for treatment of relapsing-remitting Multiple Sclerosis (RRMS), can significantly reduce exacerbations and active brain lesions. Due to concerns on infusion-related reactions (IRRs) patients should be observed during the infusions and one hour after the completion of the infusions for signs and symptoms of hypersensitivity reactions, especially in the first 12 doses. This study was conducted to see if one-hour post-infusion observation is necessary in all patients receiving natalizumab or can be wavied in some stable patients.

In this cross-sectional study, one-hour post-infusion observation was not conducted in patients who had previously received three doses of natalizumab without any history of moderate to severe or life-threatening IRRs based on the Common Terminology Criteria for Adverse Events (CTCAE) definition. Patient demographics and clinical characteristics were recorded by a trained physician in a questionnaire coupled with an emergency hotline provided for IRRs. In case of a modere to sever or life-threatening reaction during the ifusion the patient excluded from the study. Phone follow-up was done after an hour by the same medical doctor.

424 patients with MS were enrolled in this study. Fatigue (10.8%), headache (4.5%), and cough (2.8%) were the most prevalent symptoms after 1 hour from the infusions. No life-threatening complications happened for the patients. There was no significant relationship between age, gender, the interval between doses, the number of total infusions, and disease duration with the incidence of side effects.

Early discharge without one hour post-infusion monitoring can be considered for patients without any moderate to sever adverse reaction in the fisrt three infusion of natalizumab.This sterategy may reduce the costs and save the time of infusion for these patients.