P0853Safety profile of azathioprine in patients with inflammatory bowel disease in the absence of NUDT15 and TPMT polymorphism testing

Background Thiopurines remain the first-line therapy for maintenance in patients with inflammatory bowel disease (IBD), specifically in low- and middle-income countries. Available data raise safety concerns regarding the use of thiopurines. It is recommended to test for NUDT 15 and TPMT polymorphism before initiating thiopurines, which is not feasible at most centers. We aimed to assess the adverse event profile of azathioprine use in IBD patients. Methods This was a single-center retrospective study conducted at CMCTH, Bharatpur, Nepal. All the consecutive patients who visited the IBD clinic were considered for this study. Data were collected from IBD clinic files, which is a prospectively maintained data set. Short-term adverse events arising from thiopurine use were considered the primary objective of this study. The adverse events were defined as per standard definitions. The relation between the adverse events and dose and duration of azathioprine use was assessed. NUDT15 and TPMT polymorphism were not assessed in any patient before azathioprine initiation. Results Among 48 patients [UC: 20 (41.7%) and CD: 28 (58.3%)] included, 30 (62.5%) were male. The mean age and the disease duration were 41.2 ± 15.7 years and 15 (5-40.5) months, respectively. The common indications for thiopurines were steroid-dependent disease, maintenance therapy in CD, maintenance after ASUC, steroid-refractory disease, and perianal CD in 22 (45.8%), 21 (43.7%), 3 (10.7%), 1 (2.1%), and 1 (2.1%), respectively. A total of 25 (52.1%) patients on azathioprine developed adverse events [ 8 (40.0%) in UC and 17 (60.7%) in CD]. The commonest adverse events were Leukopenia in 15 (31.2%), GI intolerance in 5 (10.4%), arthralgia in 4 (8.3%), hepatitis in 3 (6.2%), and hair fall in 2 (4.1%) patients. No infection or acute pancreatitis episode was reported. A total of 16 (33.3%) patients stopped azathioprine. Adverse events were the most common cause of azathioprine withdrawal in 12 (25.0%), followed by treatment failure in 3 (6.2%), and self in 1 (2.1%). Conclusion More than half of the IBD patients on azathioprine developed adverse events. The commonest adverse events were leukopenia, GI intolerance, arthralgia, hepatitis, and hair fall. However, adverse events led to therapy discontinuation in only 12 (25%) of the patients. Conflict of interest: Dr.