Anakinra: an inhibitor of IL-1 for the treatment of rheumatoid arthritis.

Anakinra (Amgen, Inc.) is a specific receptor antagonist of IL-1 that differs from naturally occurring IL-1 receptor antagonist by the presence of a methionine group. Anakinra has been shown to be of benefit in patients with active rheumatoid arthritis, either when given alone or in combination with methotrexate, as assessed by improvement in clinical signs and symptoms, decreased radiographic progression and improvement in patient function, pain and fatigue, although it appears to be effective in fewer patients than anti-TNF agents. It has a favourable safety profile as demonstrated in clinical trials. The physician and patient must be cognizant of serious infectious episodes. Many of the rare side effects seen with TNF blockers, such as tuberculosis, other opportunistic infections, worsening of congestive heart failure and the development of demyelinating disease, have not been seen in patients treated with anakinra. Anakinra should not be given in combination with anti-TNF agents.