Vonoprazan-Related Adverse Events: A Pharmacovigilance Study Based On The FDA Adverse Event Reporting System

Yali Zhong¹Cong Hou¹Jie Zhang¹Li Wang¹Dongmei Xiong¹Huang Zhong¹Xiaobin Luo^2*

• ¹Zigong First People's Hospital Department of Gastroscopy, Zigong, China
• ²Department of Neurosurgery, Zigong Fourth People's Hospital, zigong city, China

This study comprehensively evaluated the safety profile of Vonoprazan using data from the FDA Adverse Event Reporting System (FAERS) from the first quarter(Q1) of 2023 through the first quarter(Q1) of 2025. This analysis was restricted to real-world reports collected after the U.S. approval of vonoprazan, to better reflect its current clinical use pattern in the United States. Reports in which Vonoprazan was designated as the primary suspect(PS) drug were systematically extracted, and duplicate entries were removed using MySQL(version 8.0.42). Adverse events were coded in according tothe Medical Dictionary for Regulatory Activities (MedDRA, version 24.0). To detect potential safety signals, four disproportionality methods were applied: Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), and Multi-Item Gamma Poisson Shrinker (MGPS). Differences between serious and non-serious adverse events were further examined using Pearson’s chi-square test and Fisher’s exact test. Temporal patterns of adverse event occurrence were evaluated using Time-to-Onset (TTO) analysis and Weibull Shape Parameter (WSP) modeling. In total, 978 vonoprazan-related cases were included; females accounted 62.0% of reports, and 34.3% of events were classified as serious. 47 preferred terms (PTs) met predefined signal criteria, and 16 of these, such as facial paralysis and cholecystitis, were not listed in the current U.S. FDA prescribing information for vonoprazan. Serious adverse events were more often associated with renal impairment and haematemesis, whereas non-serious events were predominantly gastrointestinal. Stratified analyses further revealed several potential high-risk signals, particularly inmale and elderly patients. The median time to onset was 7 days, and most events occurred within the first 30 days after treatment initiation. Weighted Survival Probability (WSP) analysis suggested an "early failure" pattern, and co-administration of aspirin and other acid-suppressing agents was common. In conclusion, this study provides a systematic characterization of Vonoprazan- associated adverse events and highlights several potential new safety signals that are not currently reflected in the drug's labeling, These findings should be interpreted as hypothesis-generating safety signals that may inform future prospective monitoring and clinician counseling.