Anakinra is a recombinant human interleukin-1 receptor antagonist (IL-1ra) 
recently approved by the FDA as a new therapy for patients with rheumatoid 
arthritis. Four clinical trials have been completed which have demonstrated that 
anakinra is an effective anti-rheumatic therapy either used alone or in 
combination with methotrexate. The most frequent adverse events reported in the 
clinical trials are injection-site reactions which are generally mild to 
moderate and rapidly resolve. A large, prospective safety study which allowed a 
wide-variety of comorbid conditions and concomitant medications demonstrated 
that anakinra therapy is a well-tolerated treatment for rheumatoid arthritis in 
the patient population seen by the practicing rheumatologist. Unlike therapies 
designed to affect TNF-alpha, there have not yet been reports of the development 
of tuberculosis or other fungal infections, demylinating syndromes or worsening 
of congestive heart failure. The safety profile of etanercept and infliximab 
were similar to that of anakinra in the phase I-phase III clinical trials. 
Unlike anakinra, these medications were not studied in the usual rheumatoid 
arthritis population which includes a number of patients with a wide variety of 
co-morbid disease and utilizing a number of concomitant anti-rheumatic 
medications. Post approval, several safety concerns, including patients at risk 
for serious infection and the emergence of latent tuberculosis and other 
opportunistic infections have emerged with the use of anti TNF therapy.