Simple Urine Test to Evaluate Adherence to Oral 5-ASA in Teenagers With Ulcerative Colitis: Proof of Concept. Issue 4 (October 2017)

• Record Type: Journal Article
• Authors: Dijkstra, Alie; Touw, Daan J.; van Rheenen, Patrick F.
• Is Part Of: Journal of pediatric gastroenterology and nutrition. Volume 65:Issue 4(2017)
• Publication Date: 2017-10
• Subjects: 5-aminosalicylic acid -- medication adherence -- mesalamine -- ulcerative colitis -- urine; Children -- Nutrition -- Periodicals; Pediatric gastroenterology -- Periodicals; Infants -- Nutrition -- Periodicals; Nutrition disorders in children -- Periodicals; Child Nutrition -- Periodicals; Digestive System -- growth & development -- Periodicals; Gastrointestinal Diseases -- Periodicals; Infant Nutrition -- Periodicals; Nutrition Disorders -- Periodicals; Child; 618.923
• DOI: 10.1097/MPG.0000000000001541
• Languages: English
• ISSNs: 0277-2116

Abstract

ABSTRACT: Objectives: 5-Aminosalicylic acid (5-ASA) is an important maintenance drug for patients with ulcerative colitis. A proportion of the ingested dose is excreted in the urine. Measuring 5-ASA and its metabolites in urine requires mass spectrometry, which is not widely available for this purpose. Urinary 5-ASA can be measured by colorimetry using the serum salicylic acid assay and is a surrogate marker of recent 5-ASA ingestion. We evaluated whether measuring 5-ASA in first morning voids or in random spot urine samples correctly identifies teenagers with poor adherence to oral 5-ASA. Methods: Teenagers who were prescribed a current regimen including >40 mg · kg −1 · day −1 of 5-ASA were invited to collect their spot urine with various time lapses since their last presumed 5-ASA ingestion. Classification of adherence was based on a composite method that included a patient-reported adherence scale and 6-thioguanine levels in erythrocytes. Results: Teenagers who were classified as "good adherers" had 66 of 69 (96%; 95% confidence interval 87%–99%) spot urine samples with detectable 5-ASA levels. "Poor adherers" had 30 of 45 (67%; 95% confidence interval 52%–79%) spot urine samples with un detectable 5-ASA levels. The "good adherers" with false-negative urine tests were on a once daily dosing regimen and had collected a spot urine sample shortly before the next dosage. Their first morning voids had detectable 5-ASA levels. Conclusions: Undetectable 5-ASA levels in the first morning void confirms short-term nonadherence to oral 5-ASA.