The safety of tumor necrosis factor-alpha inhibitors in the treatment of rheumatoid arthritis.

INTRODUCTION: Tumor necrosis factor inhibitors (TNFi) were the first biologic therapy authorized for rheumatoid arthritis (RA) treatment and are currently the most used biological drugs in these patients. Although clinical efficacy is proven, adverse events associated with these agents have been described, and further knowledge is essential to facilitate detection at very early stages. AREAS COVERED: We reviewed the safety profile of TNFi, including both articles and congress communications published on this topic, such as clinical trials, meta-analyses, observational studies, data from registries, and spontaneous clinical reports. We classified studies according to the most common and relevant adverse events associated with TNFi. EXPERT OPINION: There is a broad spectrum of possible adverse events associated with TNFi treatment, ranging from mild to serious, and with diverse clinical manifestations. However, most adverse events may be minimized by appropriate screening before starting treatment and with ongoing surveillance to ensure an early diagnosis. In conclusion, TNFi have a reasonable safety profile, and, globally, the benefits far outweigh the possible risk of adverse events, especially compared with the risk of the untreated underlying inflammatory condition.