Blackwell Publishing Journal Backfiles 1879-2005
Background : Poor compliance with 5-aminosalicylic acid therapy has been reported amongst patients with inflammatory bowel disease. Currently, there is no easy method to monitor 5-aminosalicylic acid; however, the chemical similarity between 5-aminosalicylic acid and salicylate might provide a solution.Aim : To determine the feasibility of using salicylate levels to monitor compliance with 5-aminosalicylic acid medication.Methods : Thirty-six patients with inflammatory bowel disease, taking maintenance 5-aminosalicylic acid, provided either a paired serum and urine sample or an intestinal biopsy. Samples were split into two: half were sent to the hospital biochemistry department for salicylate measurement, and half were analysed for 5-aminosalicylic acid and its metabolite, N-acetyl-5-aminosalicylic acid, using high performance liquid chromatography. Correlation between the results was calculated.Results : Serum and urine were available for 25 patients. Serum salicylate was undetectable, but urinary salicylate ranged from 31 to 3254 µg/mL. The correlations between urinary salicylate and 5-aminosalicylic acid and N-acetyl-5-aminosalicylic acid were 0.96 (95% confidence interval, 0.91–0.98) and 0.9 (95% confidence interval, 0.77–0.96), respectively. Sixteen biopsies were available from 13 patients. The 5-aminosalicylic acid and N-acetyl-5-aminosalicylic acid concentrations were 0.2–657 ng/mg and 1.6–1598 ng/mg, respectively; there was no correlation with bowel salicylate.Conclusions : The close correlation between 5-aminosalicylic acid and salicylate levels offers a simple method to assess compliance with 5-aminosalicylic acid therapy.
Type of Medium: