[Management of antirheumatic drugs in kidney failure]

The nephrologist deals with the management of patients with rheumatic disease, both diagnostically and therapeutically. He must determine whether the renal pathology is related to the rheumatologic disease, mostly through the use of the renal biopsy. In the second case, he must know the nephrotoxic potential of the drugs prescribed and adjust their use to the degree of renal impairment. This task is made difficult by the absence of controlled clinical trials regarding their use on patients with renal insufficiency or on chronic dialysis. For this reason, the prescription will have to take into account the pharmacokinetics of the drugs. Kidney failure can affect the metabolism of antirheumatic drugs determining their accumulation, which can lead to increased toxicity, either renal or systemic. On the other hand, dialysis can cause excessive drug removal, leading to sub-therapeutic pharmacological effects and to the need for additional doses. In this brief review, we will consider the nephrotoxic effects of some important drugs used in rheumatology and examined individually, with specific reference to rheumatoid arthritis: methotrexate, leflunamide, hydroxychloroquine, cyclosporine, biological DMARDs. In the past, therapeutic success in rheumatic diseases associated with kidney impairment was severely limited by the well- known nephrotoxicity of drugs such as gold salts, D-penicillamine, NSAIDs, COX-2 inhibitors. Although generally effective, they are contraindicated in case of kidney failure. Biologic therapies have recently opened new therapeutic perspectives. Nevertheless, it is worth stressing how our knowledge of their action is still incomplete and this may result in exposure to immune-mediated renal disease.