Review: Optimizing Adherence to Multiple Sclerosis Therapies

Disease-modifying drugs (DMDs) have transformed the treatment of relapsing-remitting multiple sclerosis (RRMS). Several studies have shown the benefits of long-term treatment in RRMS; however, all multiple sclerosis (MS) therapies are associated with treatment-related tolerability and safety issues that may challenge patient compliance with therapy. Tolerability issues include flulike symptoms and injection-site reactions for interferon β(IFNβ) and lipoatrophy and systemic postinjection reactions for glatiramer acetate (GA). Altered blood cell counts, depression, and elevated liver enzymes, including rare cases of acute liver injury, are safety issues that have been associated with IFNβand, rarely, systemic anaphylactoid reactions with glatiramer acetate. Common tolerability issues associated with natalizumab are hypersensitivity and postinfusion reactions, and mitoxantrone may cause amenorrhea, nausea, and alopecia. Serious safety issues that have limited the use of natalizumab and mitoxantrone as first-line treatments are progressive multifocal leukoencephalopathy for natalizumab and cardiotoxicity and leukemia for mitoxantrone. Although both tolerability and safety issues can affect patient adherence to therapy, numerous strategies are available to manage tolerability and monitor safety issues. Through careful monitoring of treatment-related safety issues, patient education, and tolerability management strategies, treatment nonadherence can be minimized, thereby maximizing the treatment benefits of DMDs.