Glomerular and tubular renal functions after long-term medication of sulphasalazine, olsalazine, and mesalazine in patients with ulcerative colitis

To date there are only few reports evaluating the potential nephrotoxic rea ctions of the new 5-aminosalicylic acid (5-ASA) preparations in patients wi th ulcerative colitis (UC). The aim of this study was to screen the tubular and glomerular functions in patients with UC in maintenance treatment with either 5-ASA ate-compounds (sulphasalazine and olsalazine) or mesalazine. Patients with UC in clinical remission treated with either sulphasalazine, olsalazine, or mesalazine for more than 1 year were included in an open, si ngle-blind retrospective Norwegian multicenter study. Serum and urine creat inine, serum and urine beta (2)-microglobulin, urine N-acetyl-beta -glucose amidase (NAG), urine alkaline phosphatase, urine microalbumin, urine alanin e amino peptidase, and urine beta (2)-microglobulin were measured. Fifty-tw o females and 75 males (n = 127), ages 20-69, were evaluated. Thirty-six pa tients were treated with sulphasalazine (mean treatment time 10.1 +/- 6.6 y ears [mean +/- SD]), 32 patients were treated with olsalazine (2.3 +/- 1.4 years), and 59 patients with mesalazine (3.2 +/- 2.0 years). At inclusion, there were no significant differences in the serum or urine values between the groups. In 17 patients (1 patient [3%] in the sulphasalazine group, 4 p atients [13%] in the olsalazine group, and 12 patients [20%] in the mesalaz ine group), at least one abnormal serum and/or urine value was detected. Af ter 10 years of treatment, only one abnormal value was found among the 19 p atients in the sulphasalazine group. The abnormal values observed in the ot her groups indicated minor glomerular or tubular renal damage. In conclusio n, long term sulphasalazine treatment appears to be safe and free of nephro toxic side effects, whereas minor glomerular and tubular impairment are obs erved in a few patients treated with olsalazine and mesalazine.