Cyclosporine: nephrotoxic effects and guidelines for safe use in patients with rheumatoid arthritis.

Renal abnormalities occur frequently in patients with rheumatoid arthritis; they may be complications of the rheumatoid disease process itself (amyloidosis) or may result from various therapies including gold compounds, D-penicillamine, analgesics such as aspirin or phenacetin used long term, and nonsteroidal anti-inflammatory drugs. Cyclosporine, a highly effective immunosuppressive agent currently under investigation as a treatment for RA, is also known to produce renal dysfunction. Some forms of functional and structural tubular changes appear readily reversible. Others associated with renal vasculopathy and interstitial fibrosis can lead to irreversible nephrotoxicity. A clear understanding of the pharmacology, drug interactions, and types of renal side effects encountered with cyclosporine can lead to a reduction of adverse renal reactions. Similarly, an understanding of which patients are at high risk for renal dysfunction can lead to safer and more efficacious use of this potent immunosuppressive agent.