Is tiaprofenic acid different from other NSAIDs with regard to effects on renal function in the elderly?

In a study of the effects of various NSAIDs on renal function in the elderly, indomethacin, tiaprofenic acid and sulindac were administered to patients ranging in age from 54 to 97 years for a period of 3 months. Indomethacin sustained release (25 mg tid) was administered to 66 patients, tiaprofenic acid (200 mg tid) to 54 patients, and sulindac (100 mg tid) to 59 patients. A control group, to whom no NSAIDs were administered, comprised 60 patients. Renal function before and after NSAID administration was compared, the parameters investigated being blood urea nitrogen (BUN), serum creatinine (SCR), and serum beta 2-microglobulin (beta 2-m) concentrations. Patients whose levels of BUN, SCR and beta 2-microglobulin were all within normal ranges at the beginning of the study were considered to have 'normal' renal function; those who showed an abnormal value for at least 1 of the 3 parameters were considered to have 'abnormal' renal function. The administration of indomethacin resulted in a significant increase in the serum creatinine concentration, and in the normal renal function subgroup, a significant increase in BUN. Sulindac administration resulted in a significant increase in BUN and beta 2-microglobulin concentrations, but no significant change in serum creatinine. In comparison, the administration of tiaprofenic acid resulted in no significant changes in any of 3 parameters. An additional study of the effects of 4 weeks' administration of the same NSAIDs on N-acetyl-beta-D-glucosaminidase concentrations in the urine of elderly patients revealed no significant changes with any of the 3 drugs. This suggests that the drugs do not damage the proximal tubules.