Objective To analyze potential adverse drug events(ADEs) associated with ustekinumab and upadacitinib in the treatment of inflammatory bowel disease(IBD) based on an international authoritative database, thereby providing evidence for clinical medication safety.

Methods Data were extracted from the Food and Drug Administration Adverse Event Reporting System(FAERS) database using OpenVigil 2.1. ADE reports were collected for ustekinumab(from Q3 2017 to Q1 2025) and upadacitinib(from Q3 2019 to Q1 2025), where each drug was identified as the primary suspected medication for IBD. Signal detection and statistical analysis were performed using the reporting odds ratio(ROR) and proportional reporting ratio(PRR) methods.

Results A total of 3648 ADE reports for ustekinumab and 3812 for upadacitinib, with each as the primary suspected drug in IBD treatment, were retrieved. Using the ROR-PRR combined detection method, relevant ADE signals were identified. High-frequency ADEs associated with ustekinumab included hypersensitivity reactions, various infections, and brain fog, while those associated with upadacitinib included acne, flatulence, and herpes zoster. System organ class(SOC) analysis of positive signals indicated that both drugs commonly caused ADEs in categories such as Infections and infestations, Gastrointestinal disorders, Nervous system disorders, Skin and subcutaneous tissue disorders, and Respiratory, thoracic, and mediastinal disorders. Among these, Infections and infestations were the most frequent SOC, involving preferred terms such as Escherichia sepsis and Pneumococcal pneumonia.

Conclusions Ustekinumab and upadacitinib exhibit distinct safety profiles in the treatment of IBD. In addition to known ADEs described in the prescribing information, ustekinumab requires close monitoring for hypersensitivity reactions, opportunistic infections, and potential neurological risks. For upadacitinib, attention should be paid to risks of acne, herpes zoster, hypercholesterolemia, and thrombotic events. These findings provide important safety information to support individualized clinical decision-making in IBD management.