Adverse drug events associated with tiotropium: a real-world pharmacovigilance study of FDA adverse event reporting system database

Introduction Tiotropium, a long-acting muscarinic antagonist, is commonly employed for the maintenance treatment of chronic obstructive pulmonary disease (COPD) and asthma. While its efficacy has been validated through numerous randomized controlled trials, safety concerns in real-world post-marketing settings necessitate further evaluation. Aim This study aimed to analyze the adverse events (AEs) associated with tiotropium reported in the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS) database to identify potential safety signals. Methods A retrospective analysis was conducted on adverse reaction reports related to tiotropium in the FAERS database from the first quarter of 2004 to the fourth quarter of 2024. The AE names in the FAERS database were systematically classified using the Preferred Terms (PTs) and System Organ Classes (SOCs) provided by the latest version of the Medical Dictionary for Regulatory Activities (MedDRA 27.1). After deduplication, a combination of methods, including the Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), and Multi-item Gamma Poisson Shrinker (MGPS), was employed for disproportionality analysis. Results A total of 129,763 AE reports related to tiotropium were included in the analysis, affecting 65,045 patients. These reports encompassed 27 different SOC categories, identifying 264 AEs associated with tiotropium. After excluding certain AEs deemed clinically insignificant, the most common AEs reported were dyspnea (n = 8,600), cough (n = 2,440), and pneumonia (n = 2080). The AEs exhibiting the highest signal strength included aggravated dyspnea (ROR: 162.04), hoarseness (ROR: 43.42), and aggravated chronic obstructive airway disease (ROR: 43.17). Additionally, we identified potential risks not mentioned in the instructions (United States Prescribing Information and the Canadian Product Monograph), such as epiglottic cancer, halo vision, and malignant lung tumors. Conclusion This study offers a more comprehensive understanding of tiotropium by uncovering previously unreported adverse reactions. Physicians should take these newly identified adverse reactions into account when prescribing this medication.