5-aminosalicylic acids and the risk of renal disease: A large British epidemiologic study

Background & Aims: This study was performed to quantify the risk of renal disease in patients using aminosalicylates (5-ASA). Methods: Data from the United Kingdom General Practice Research Database were used to estimate the incidence of renal disease in adult patients with inflammatory bowel disease (IBD) or prescription for 5-ASA and in patients without IBD. In a nested case-control analysis, each case of renal disease was matched to 5 controls. Results: Among the 19,025 5-ASA users with IBD, 1.30 patients developed renal disease (incidence rate of 0.17 cases per 100 patients per year). The incidence among patients with IBD but without 5-ASA use was 0.25 and among patients without IBD was 0.08. In the case-control analysis, the crude odds ratio (OR) for renal disease in current 5-ASA users was 1.60 (95% confidence interval [95% CI]: 1.14-2.26); the adjusted OR was 0.86 (95% CI: 0.53-1.41). For recent users, the crude OR was 4.18 (95% CI: 2.59-6.76) and adjusted OR 2.48 (95% CI: 1.33-4.61); for past users (last prescription more than 12 months before), 1.71 (95% CI: 1.09-2.70) and 0.99 (95% CI: 0.55-1.76), respectively. Although the numbers were small, mesalazine and sulfasalazine users had comparable risks (crude OR for current and recent users of OR 2.08 [95% CI: : 1.44-3.01] and 1.84 [95% CI: 1.20-2.82], respectively). In only a few records was renal disease attributed to interstitial nephritis or 5-ASA use. Conclusions: Users of 5-ASA have an increased risk of renal disease that may be partly attributable to the underlying disease. Although renal disease is a recognized adverse effect of 5-ASA, the incidence appears to be low and does not appear to be related to either the dose or type of 5-ASA used.