Premium
Is your patient taking the medicine? A simple assay to measure compliance with 5‐aminosalicylic acid‐containing compounds
Author(s) -
Shaw I. S.,
Jobson B. A.,
Silverman D.,
Ford J.,
Hearing S. D.,
Ball D.,
Johnson E.,
Day A.,
Probert C. S. J.
Publication year - 2002
Publication title -
alimentary pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.308
H-Index - 177
eISSN - 1365-2036
pISSN - 0269-2813
DOI - 10.1046/j.1365-2036.2002.01375.x
Subject(s) - aminosalicylic acid , medicine , urine , salicylic acid , gastroenterology , mesalazine , confidence interval , ulcerative colitis , chemistry , biochemistry , disease
Summary 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.