List of products in the National Drug Code with proprietary name . This medication is used alone or with other medications to treat moderate to severe rheumatoid arthritis. It helps to reduce pain and swelling due to rheumatoid arthritis. Sarilumab belongs to a class of drugs known as monoclonal antibodies. It works by blocking Interleukin-6, a substance made by the body that causes swelling (inflammation) in areas affected by rheumatoid arthritis.