ABSTRACT
BACKGROUND AND PURPOSE: The number of disease-modifying drugs (DMDs) available for treating relapsing-remitting multiple sclerosis is increasing. Numerous drugs have been approved since 2010 in South America, which has increased the complexity of the treatment algorithm. The aim of this study was to determine the changes in multiple sclerosis treatments relative to the underlying causes and the availability of new DMDs in Argentina. METHODS: A descriptive retrospective study was carried out on a group of 59 patients diagnosed with RRMS who use more than one DMD. RESULTS: The first treatment switch occurred before 2010 in 27% of the patients and after 2010 in the other 73%. Efficacy was the main reason for switching during both periods. A second treatment switch was required in 25% of the patients, with this occurring after 2010 in 86.6% of them. Interferon was the most-used drug before 2010 and fingolimod was the most-used drug thereafter. CONCLUSIONS: We have identified that the tendency for treatment changes has increased following the arrival of new drugs. Efficacy has been the main cause of these changes.