Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS), which ultimately leads to myelin damage and axonal loss. The disease is complex and multifactorial, but the key pathogenic event appears to be an uncontrolled response of components of the immune system (T and B lymphocytes) to myelin proteins. No definitive treatment is available for MS, however immunomodulatory and immunosuppressant drugs act as disease-modifying agents (DMDs).