Avonex is a brand-name immunomodulator medication that is typically used to manage the symptoms of multiple sclerosis, or MS. Avonex is used to help slow the progression of disability associated with multiple sclerosis, and ward off episodes where symptoms strike. Multiple sclerosis is a disease that affects the nerves, resulting in lack of muscle coordination, weak muscles, poor bladder control, difficulty speaking, and vision problems. The generic name for Avonex is interferon beta-1a. Avonex is a liquid medication that is injected beneath the skin, typically three times per week, and usually on the same three days each week. Avonex has only been found to be effective against relapsing-remitting MS, but is not effective against chronic progressive MS.