Multiple Sclerosis- Pharmacist
Multiple sclerosis (MS) is a chronic inflammatory and degenerative disease of the central nervous system (CNS) generally affecting the brain, spinal cord and optic nerves. It is characterized by demyelination of nerve fibers (axons) and subsequent loss of neuronal transmission. At least 400,000 Americans and over 2 million people worldwide have MS; it is not a rare disease. Its onset is usually between the ages of 20 and 50 years old, but it can appear in children as well as older adults. Women are affected 2 to 3 times more often than men. MS has a variable clinical course that is generally progressive, leading to some degree of disability over time in the majority of patients. It is the leading cause of non-traumatic disability in young adults; without treatment, about half of patients require a cane to walk 10 years following diagnosis and about 15% require a wheelchair. The cause of MS remains unknown; however, research in this area is rapidly growing. Current theories suggest a complex relationship among certain environmental and genetic factors and the immune system.
Before the release of the first disease-modifying drug (DMD), interferon beta 1b (IFN-ß1b) in 1993, the available medications for MS targeted only the relief of symptomatic problems. Today, a total of 9 DMDs are approved for use in the US for relapsing forms of MS. Research has suggested that neurological damage early in the course of MS results in long-term neurological impairment. Consequently, many experts recommend early initiation of treatment with DMDs, at the time of the first attack – even before a definite diagnosis can be made – if the patient has magnetic resonance imaging (MRI) findings consistent with MS.
DMDs are not a cure, but can reduce the frequency of relapses and may reduce the progression of disability. DMDs differ in their mechanisms of action, routes of administration, and side effects. Because treatment is usually lifelong, individualization of DMD therapy is critical to minimize side effects and maintain adherence.
This issue provides an overview of MS and an update on the drugs used to manage the disease, including DMDs and medications used to treat associated symptomatic conditions. The primary focus will be on relapsing forms of MS and the newer, orally administered agents: fingolimod (Gilenya®), teriflunomide (Aubagio®), and dimethyl fumarate (Tecfidera™).