Interferon beta-1b injection site reactions and necroses

Abstract

We conducted a comprehensive review of selected adverse event reports that were submitted to the Food and Drug Administration (FDA) for interferon beta-1b during the first 30 months following licensure. The adverse events reviewed were injection site reactions, injection site necroses, and non-injection site necroses. These adverse events were selected because of the relative frequency of injection site reactions and because of the severity and sequelae of certain injection site and non-injection site necroses. Our review enabled us to characterize the clinical presentation and the treatment received, which were not described in the package insert or by the IFNB (interferon beta-1b) Multiple Sclerosis Study Group publication. The time of onset of the adverse events ranged from 1-29 months after initiation of interferon beta-1b treatment, with a mean of 1 month. In general, the more clinically significant adverse events (i.e., injection site necrosis and non-injection site necrosis) developed more slowly than the injection site reactions. Greater than 85% of the adverse events presented with one or two signs/symptoms, although the number of signs/symptoms ranged from 1-8. No predominance of treatments for the adverse events was observed. The most striking finding was that the overall sex ratio, which could be due to reporting artifacts, was 8.1: 1 female: male.