P460 A Real-World Picture of Adverse Drug Reactions in Inflammatory Bowel Disease

Lemos Garcia, J.(1);Rosa, I.(2);Saraiva, S.(2);Moleiro, J.(2);Claro, I.(2);

(1)Instituto Português de Oncologia de Lisboa Francisco Gentil, Gastroenterology, Lisbon, Portugal;(2)Instituto Português de Oncologia de Lisboa: Instituto Portugues de Oncologia de Lisboa Francisco Gentil EPE, Gastroenterology, Lisbon, Portugal;


Patients with Inflammatory Bowel Disease (IBD) face complications of medical treatment that may compromise their health and the drugs’ therapeutic success. Real world data regarding adverse drug reactions (ADR) is crucial.


Unicentric retrospective study. All patients followed for IBD in a tertiary Portuguese hospital between 2015-2021 were included.


328 patients included-55.8% women; age at last follow-up 53.4±16.7 years old; Crohn’s Disease (CD) in 53.0%; follow-up of 15.8±10.8years. Extraintestinal manifestations(EIM) occurred in 13.1%(n=43) patients, mostly arthropathy/arthritis(n=33). Current or previous treatment included salicylates in 69.5%, thiopurines 63.1%, corticosteroids 54.3%, methotrexate 5.5%, infliximab 38.4%, adalimumab 11.6%, ustekinumab 4.9% and vedolizumab 4.6%. In total, 124 ADR occurred in 97 patients(28.7%). ADR occurred with salicylates in 20/228 patients(8.8%), corresponding to 9/215 of mesalazine and 10/26 of salazopyrin treated patients, mostly gastrointestinal(GI) intolerance(n=8). ADR occurred in 78/207(37.7%) of thiopurine-treated patients; 5 had more than one ADR to thiopurines and 10 developed ADR despite change from azathioprine to 6-mercaptopurine. Reactions included myelosuppression(n=21), GI symptoms(n=20), pancreatitis(n=8). One case of corticosteroid ADR was reported (psychosis). 4/18(22,2%) methotrexate-treated patients experienced ADR, all liver toxicity. Infliximab-associated ADR occurred in 20/126 patients(6.1%), namely infusion reactions(n=7) or lupus-like syndrome(LLS) (n=6). 9/39 adalimumab-treated patients experienced ADR, such as skin rash(n=3). No reported ADR with ustekinumab or vedolizumab. Overall, ADR led to dose adjustments in 100/120 cases and to drug suspension in 22. Nine patients needed hospital admission and one died with squamous cell carcinoma in fistula tracts. 94.9% of these ADR remitted. In the univariate analysis, ADR were associated with IBD type(p=0.040), EIM(p=0.001), UC extent(p=0.016), thiopurine(p<0.001), infliximab(p<0.001) and adalimumab (p=0.005) exposure. In multivariate analysis, significance was kept with EIM(p=0.003), thioupurine(p=0.006) and infliximab(p=0.003) exposure. Patients who had one ADR, were not more likely to have ADR with other drugs.


ADR occurred in 28.7% of IBD patients and the most commonly implicated drugs were salazopyrin (10/26, 38.5% of patients) and thiopurines (75/207, 36.2%), rates much higher than those found with mesalazine and biologics. Nevertheless, most of these reactions resolved with dose adjustments or drug suspension, without hospital admission. This indicates that drugs available for IBD treatment remain safe, but their use must be cautious and toxicities should be monitored.