Clinical assessment of the renal toxicity of antirheumatic drugs.

Antirheumatic drugs may cause a significant, although generally reversible, reduction of GFR, RPF, CNa and hyperkalemia in a wide range of extrarenal and renal disease states (severe liver disease, congestive heart failure, SLE, nephrotic syndrome, etc.); chronic ingestion has been associated with analgesic nephropathy. Recently cases have been reported of reversible acute renal failure with massive proteinuria and interstitial nephritis. The acute effects of a renal PG-inhibiting (ibuprofen) or a renal PG-sparing (sulindac) cyclo-oxygenase inhibitor on renal functional parameters (GFR, RPF, CNa, CK, urine volume) and proteinuria have been studied in 24 patients with clinically and biopsy proven chronic glomerular disease; in all patients ibuprofen significantly reduced GFR, RPF, CNa; these changes were fully reversible within a week of withdrawal of the drugs. A causal relationship exists between inhibited PG-synthesis and reduced renal function in these patients, since sulindac, which failed to reduce urinary PG excretion did not alter significantly the renal function. Moreover proteinuria is not reduced by ibuprofen at doses comparable, as far as concerns inhibition of PG-synthesis, to those of indomethacin.