Background: 5-Aminosalicylate acid (5-ASA) is a crucial drug for ulcerative colitis (UC) patients. 5-ASA has several side effects. However, the types of side effects vary and are sometimes severe.
Methods: A single-center, retrospective cohort study was conducted from September 2001 to June 2020. We surveyed consecutive UC patients who visited our hospital and investigated adverse drug reactions (ADRs) related to 5-ASA formulations. We grouped patients into four subgroups: (1) lupus-like symptoms, (2) blood test abnormalities, (3) mimicking IBD exacerbation and (4) others. Their clinical courses were evaluated.
Results: We surveyed 288 consecutive UC patients, 35 of whom developed ADRs of any grade (12.9%), and analyzed 27 patients. The median age and 5-ASA doses were 43 years and 4000 mg, respectively, and 48% were male. The ADR triggers were the first use of 5-ASA (n = 17, 63%), 5-ASA switch (n = 9, 33%) and 5-ASA dose escalation (n = 1, 3.7%). The median time to ADR was 15 days (IQR: 7, 63). Ten patients (37%) had grade 3/4 ADRs. Fever was the most common ADR (n = 6, 23%), followed by hyperamylasemia and headache (n = 4, 15%). Lupus-like symptoms accounted for 56% (n = 15), blood test abnormalities for 26% (n = 7), mimicking IBD exacerbation for 15% (n = 4) and others for 3.7% (n = 1). The time to ADR was shorter in the mimicking IBD exacerbation group (median 11 days) than in the lupus-like symptoms (22 days) and blood test abnormalities (55 days) groups.
Conclusion: Classification of ADRs related to 5-ASA into four groups might lead to early recognition of ADRs.
Keywords: 5-ASA intolerance; 5‐Aminosalicylate acid; adverse drug reactions; allergy; ulcerative colitis.