Optimizing the benefit of multiple sclerosis therapy: the importance of treatment adherence.

Poor treatment adherence is problematic in many therapy areas, including multiple sclerosis (MS). Several immunomodulatory drugs are available for the treatment of MS, all of which require frequent parenteral administration. Current first-line therapies are two formulations of interferon (IFN) beta-1a, one of IFN beta-1b, and one of glatiramer acetate. Discontinuation of treatment is common, particularly in the first few months after initiation. Although the true effect of poor adherence to MS therapy is not known, it is likely to lead to a fall in treatment efficacy. Many factors influence a patient's adherence to treatment, including the patient's MS subtype and disability level, cognitive impairment resulting from MS, perceived lack of efficacy of the prescribed medication, and adverse events associated with MS therapy. This article summarizes the barriers to adherence to MS therapies, and discusses patient management strategies that can be employed to encourage adherence. Future advances in the field of MS treatment will be explored, including the development of orally administered drugs, which may enhance adherence.