To explore post-marketing adverse drug events (ADE) of avacopan and explore the risk factors for severe ADE, providing a reference for clinical safe and rational drug use.

Retrieved adverse event report information associated with avacopan from the U.S. Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) database were extracted, covering a total of 12 quarters from the fourth quarter of 2021 to the third quarter of 2024. Suspicious AEs were screened using the reporting odds ratio (ROR), proportional reporting ratio (PRR), bayesian confidence propagation neural network (BCPNN), multiple item empirical bayesian gamma poisson shrinker (MGPS) based on disproportionality analysis. Univariate and multivariate logistic regression analyses were conducted on severe ADE to explore the risk factors associated with avacopan-induced severe ADE according to their severity.

A total of 2 886 ADE reports associated with avacopan were obtained, including 1 489 reports of severe AEs. Using the disproportionality analysis methods, a total of 69 positive ADE signals were identified for avacopan, involving 14 systems and organs. The ADE associated with avacopan were sorted by frequency of occurrence, with hospitalisation (272 cases) having the highest number of reports. By signal strength, antineutrophil cytoplasmic antibody increased showed the strongest signal (ROR=290.83, 95%CI=114.09~741.35). The results of the Logistic regression analysis showed that gender (OR=1.27, 95%CI=1.02~1.58, P<0.05), age (65~80 years: OR=2.20, 95%CI=1.61~2.99, P<0.001；≥80 years: OR=4.61, 95%CI=2.89~7.34, P<0.001) and multiple medications (<5 prescribed drugs: OR=1.32, 95%CI=1.05~1.66, P<0.05; ≥5 prescribed drugs: OR=12.22, 95%CI=6.83~21.87, P<0.001) were the influencing factors for occurrence of severe ADE associated with avacopan.

Clinicians and pharmacists are advised topay greater attention to severe and new ADE signals not included in drug labeling. They should enhance management and pharmaceutical care for elderly, female, and polypharmacy patients to prevent serious ADE and ensure the patient medication safety.