[Interferon beta as a therapy for múltiple sclerosis]
Introduction of interferon beta in multiple sclerosis treatment represented a great advance: they are efficacious drugs, capable of reducing rate and severity of relapses, besides improving disease parameters, measured by MR imaging techniques. However, some controversy has been raised on optimal doses, ways and frequency of administration. In this article, the authors review studies about the efficacy of the existing products, as well as evidences for and against a dose-effect relationship. Although differences in clinical trials make comparisons difficult, available data indicate that efficacy of the three products is quite similar. There is no basis to believe that an increase in dose or frequency over those used in phase III trials may lead to a parallel efficacy improvement.