Renal impairment associated with non-steroidal anti-inflammatory drugs.

We have compared the renal function on admission and discharge of 22 patients routinely admitted to our rheumatology ward. None had previously diagnosed renal failure. Of 11 patients in whom we stopped long term non-steroidal anti-inflammatory drug (NSAID) therapy, all showed a rise in creatinine clearance (Ccr) after three to 28 days. In contrast, a control group comprising 11 similar patients who continued to receive NSAIDs showed no significant change. Recent work has suggested that it is possible to identify patients at risk of developing nephrotoxic side effects with NSAIDs. Based on these criteria (but excluding age alone as a risk), six patients from the first group and 10 from the second group would have been without risk. We infer from this that asymptomatic, reversible impairment of renal function is common, and that the potential clinical benefit from the use of NSAIDs should be balanced against this predictable toxicity.