MULTIPLE SCLEROSIS: Edited by Giancarlo ComiPrevention and management of adverse effects of disease modifying treatments in multiple sclerosisMoiola, Luciaa; Rommer, Paulus S.b; Zettl, Uwe K.cAuthor Information aDepartment of Neurology, Multiple Sclerosis Center, IRCCS Ospedale San Raffaele, Milan, Italy bDepartment of Neurology, Medical University of Vienna, Vienna, Austria cNeuroimmunology Section, Department of Neurology, University of Rostock, Rostock, Germany Correspondence to Paulus S. Rommer, Department of Neurology, Medical University of Vienna, Spitalgasse 23, 1090 Vienna, Austria. E-mail: Paulus.email@example.com Current Opinion in Neurology: June 2020 - Volume 33 - Issue 3 - p 286-294 doi: 10.1097/WCO.0000000000000824 Buy Metrics Abstract Purpose of review To summarize the currently known side effects of the approved therapies of multiple sclerosis and to suggest monitoring procedures. Recent findings The progress in the treatment of multiple sclerosis with new very effective therapies is accompanied by a number of side effects. Some of these have already been described in the approval studies, but some only after approval in a real world situation. The reason for this is the short duration of the clinical studies, the very heterogeneous patient profile in the real world setting with a number of comorbidities, pretherapies, and wider age range. The side effects may occur during application of therapies or afterwards during the course of the treatment. The side effects may range from mild infections, mild laboratory abnormalities, secondary autoimmune diseases to life-threatening side effects such as progressive multifocal leukoencephalopathy. Summary It has to be pointed out that these side effects are not to be considered as final and neurologists should be vigilant against new unknown side effects. The doctor should be aware of these undesirable effects, should weigh the benefits of the therapies against the risks, but at the same time she/he should keep in mind that multiple sclerosis can be a very disabling disease if not treated properly. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.