John J. Cush, MD 
Chief, Rheumatology and Clinical Immunology 
Presbyterian Hospital of Dallas 
Clinical Professor of Internal Medicine
The University of Texas Southwestern Medical School
Dallas, TX

Summary Points

• The most common side effect of self-administered biologics is injection site reaction, but this led to discontinuation of the drug in less than 5% of cases. 
• Serious adverse events due to biologics appear to occur at rates of less than 1 case per 1,000 patient-years. 
• Surveillence should be maintained for serious infections including TB, demyelinating disorders, pancytopenia, congestive heart failure, malignancy including lymphoma, drug-induced lupus, and hepatotoxicity.

Introduction
In the past 5 years, several biologic agents have been approved for use in rheumatoid arthritis (RA). These drugs are capable of selectively disarming key effector molecules critical to the inflammatory process. The clinical potential of these agents has been demonstrated in many well-done randomized, controlled clinical trials. Utilization of these novel compounds is often tempered by cost, limited exposure, and safety concerns (1).

Because of the popularity of these agents with patients and rheumatologists alike, clinicians must be prepared to discuss the potential risks associated with biologic therapies as they begin to appear with greater frequency in practice. This article will focus on the safety issues arising from clinical trial and postmarketing experience with adalimumab, etanercept, infliximab, and anakinra (2,3,4,5,6,7).