Pharmacovigilance in Action: Utilizing VigiBase Data to Improve Clozapine Safety

Signal detection of ferric carboxymaltose-induced serious adverse events: disproportionality analysis of FAERS and VigiBase data and systematic review of case reports

PURPOSE

The recent surge in serious adverse events (SAEs) and deaths associated with ferric carboxymaltose (FCM) underscores the importance of evaluating its safety profile.

METHODS

We conducted a retrospective case/non-case study from Q4 of 2003 to Q4 of 2024 data on FCM in the FDA Adverse Event Reporting System (FAERS) and VigiBase databases. Signal detection was performed using proportional reporting ratio (PRR), reporting odds ratio (ROR), and information component (IC). The influence of concomitant medication on the identified signal was assessed and refined using Open Vigil 2.1. Additionally, to identify case reports on FCM-induced adverse events, a comprehensive search was performed in PubMed, Google Scholar, and Scopus databases from inception to April 12, 2025.

RESULTS

In the FAERS database, 46 deaths were reported in connection with FCM, though no significant death signal was observed (PRR = 0.3, LB (lower bound) ROR = 0.2, IC025 = - 2.3). Nonetheless, positive safety signals emerged for SAEs such as anaphylactic shock (PRR = 3.9, LB ROR = 2.3, IC025 = 1.0), circulatory collapse (PRR = 14.6, LB ROR = 10.5, IC025 = 3.1), respiratory distress (PRR = 9.6, LB ROR = 7.1, IC025 = 2.6), hypophosphatemia (PRR = 520.7, LB ROR = 530.1, IC025 = 8.0), and arrhythmia (PRR = 3.3, LB ROR = 2.2, IC025 = 1.0). After meticulously refining our analysis to account for the influence of concomitant medications, we observed that the strength of all signals remained unchanged, except for respiratory distress, bradycardia, hypotension, abdominal pain, and urticaria. Analysis of VigiBase data revealed 42 reported fatal cases and potential signals for hypersensitivity (PRR = 4.5, LB ROR = 4.4, IC025 = 2.1), anaphylactic shock (PRR = 2.3, LB ROR = 1.9, IC025 = 0.9), circulatory collapse (PRR = 7.2, LB ROR = 6.0, IC025 = 2.5), respiratory distress (PRR = 6.9, LB ROR = 5.7, IC025 = 2.5), and hypophosphatemia (PRR = 245.1, LBROR = 234.8, IC025 = 7.5) with Ferinject. The systematic review of 11 case reports emphasized SAEs linked to FCM, thereby strengthening this association.

CONCLUSION

This study reveals that FCM carries SAEs. Providers must weigh the benefits and risks on a case-by-case basis, considering patient-specific factors. Continuous monitoring and further research are crucial for the safe use of FCM in iron deficiency anemia.

Association of Glucagon-like Peptide-1 Receptor Agonists with Optic Nerve and Retinal Adverse Events: A Population-Based Observational Study Across 180 Countries

PURPOSE

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are important therapeutic options for type 2 diabetes and obesity; however, concerns about ophthalmic safety persist. This study examined associations between GLP-1 RAs and ocular adverse events (AEs).

DESIGN

Global observational pharmacovigilance study.

METHODS

We searched the US FAERS database (via OpenVigil 2.1) and WHO's VigiBase (via VigiAccess) for optic nerve and retinal AEs associated with semaglutide and tirzepatide, covering the period from their respective approval dates-December 2017 for semaglutide and May 2022 for tirzepatide-through September 2024. In FAERS, all other drugs were compared, while in VigiBase, metformin, empagliflozin, dulaglutide, and insulin served as controls. Disproportionality metrics included reporting odds ratios (RORs) with 95% confidence intervals.

RESULTS

Semaglutide and tirzepatide accounted for 76,444 cases (0.59%) in FAERS (n=12,936,341) and 118,639 cases (0.34%) in VigiBase (n>35,000,000). Semaglutide showed significantly higher odds of ischemic optic neuropathy (ION) (FAERS: ROR=11.12, 95%CI=8.15-15.16; VigiBase: ROR=68.58, 95%CI=16.75-280.67), diabetic retinopathy (DR) (FAERS: ROR=17.28, 95%CI=13.62-21.91; VigiBase: ROR=7.81, 95%CI=5.60-10.90), as well as retinal/vitreous detachment, retinal/vitreous hemorrhage, and retinal tear (FAERS: ROR=2.44-5.89, 95%CI=1.70-8.97, all p<0.001, IC025=0.49, compared to all other drugs. VigiBase: ROR=5.49-20.91, 95%CI=2.71-90.11, all p≤0.0001, IC025≥0.53, compared to metformin). Unique to VigiBase were macular edema (ROR=3.87, 95%CI=1.89-7.92), macular hole (ROR=20.90, 95%CI=2.65-165.01), and papilledema (ROR=6.97, 95%CI=2.53-19.17) (all p≤0.004, IC025≥0.27, compared to metformin). Sensitivity analyses using empagliflozin and dulaglutide revealed significant associations with ION and DR, while vitreous detachment and hemorrhage were significant when compared to dulaglutide. Additionally, when insulin was used as a comparator, semaglutide showed a higher ROR for ION (ROR=9.84, 95%CI=4.25-22.81, P<0.0001, IC025=0.42). However, tirzepatide was only significantly associated with DR in FAERS.

CONCLUSIONS

Given the widespread use of semaglutide, its association with ocular AEs highlight the need for global pharmacovigilance and post-marketing surveillance.

Letter to the FDA Proposing Major Changes in the US Clozapine Package Insert Supported by Clozapine Experts Worldwide. Part II: A Review of Fatal Outcomes in US Pharmacovigilance Data and Proposed Changes

PURPOSE/BACKGROUND

This is the second part of a 2-part article that proposes improving the United States (US) clozapine package insert. Part II focuses on fatal outcomes and the 5 boxed warnings, 4 specifically for clozapine: severe neutropenia, seizure, orthostatic hypotension and myocarditis, and 1 for all antipsychotics (elderly with dementia).

METHODS

US reports to the World Health Organization's global pharmacovigilance database were analyzed from clozapine's introduction to January 15, 2023.

FINDINGS/RESULTS

The US was the top reporter worldwide for clozapine with 56,003 reports and 9587 associated fatal outcomes. The 4 clozapine boxed warnings were associated with 534 fatal outcomes (218 with severe neutropenia, 131 with seizures, 125 with orthostasis, 36 with myocarditis, 24 with cardiomyopathy, and 0 with mitral valve prolapse). With no boxed warnings, pneumonia was associated with 674 fatal outcomes and increased white blood cell count (a sign of infection) with 596 fatal outcomes. After considering overlaps, pneumonia and increases in white blood cell count explained 900 fatalities, or 9.4% of 9587 fatal outcomes. The Food and Drug Administration continues to focus on severe neutropenia which was associated with only 218 or 2.3% of fatal outcomes, whereas 97.7% of fatal outcomes reported in US clozapine-treated patients had another cause.

IMPLICATIONS/CONCLUSIONS

To help prevent future deaths in clozapine-treated patients, the clozapine package insert should focus on fatal outcomes during infections. Part II offers detailed solutions regarding current boxed warnings and lack of a warning for pneumonia and other infections. The Supplementary Material includes letters of support from 124 non-US clozapine experts from 44 countries/regions who support Parts I and II.

Global and regional estimates of vaccine-associated herpes zoster and their related vaccines from 1969 to 2023

Vaccine-induced immunosuppression can reactivate the varicella-zoster virus, potentially leading to the development of herpes zoster. However, the literature on this topic is inconsistent, resulting in limited clarity. Therefore, we aimed to enhance our understanding of vaccine-associated herpes zoster and establish guidelines for future research, utilizing a global database to improve global public health. We investigated vaccine-associated adverse events in herpes zoster using reports (~ 13 million reports) from the WHO international pharmacovigilance database. Data were analyzed for the global number of reports, reported odds ratios (ROR), and information components (IC) to determine the potential association between 18 vaccines and vaccine-associated herpes zoster reports in nearly 170 countries and territories from 1969 to 2023. Of 7,805,380 vaccine-associated adverse events, there were 51,985 herpes zoster reports. Vaccine-associated herpes zoster showed the highest strength of association with COVID-19 mRNA vaccines (ROR, 11.85 [95% CI, 11.70-12.01]; IC, 2.74 [IC0.25, 2.72]), followed by encephalitis (ROR, 4.07 [95% CI, 3.37-4.92]; IC, 2.00 [IC0.25, 1.68]), influenza (ROR, 3.44 [95% CI, 3.28-3.62]; IC, 1.77 [IC0.25, 1.69]), and ad5-vectored COVID-19 vaccines (ROR, 3.05 [95% CI, 2.97-3.14]; IC, 1.54 [IC0.25, 1.50]). The ROR and IC of vaccine-associated herpes zoster in males (ROR, 7.94 [95% CI, 7.80-8.08]; IC, 2.47 [IC0.25, 2.45]) and females (ROR, 6.71 [95% CI, 6.62-6.80]; IC, 2.30 [IC0.25, 2.28]). The ROR and IC increased with advancing age. Our findings emphasize the need to consider the immune status of vaccine recipients and to implement appropriate compensation and management manuals for vaccine-associated herpes zoster.

Evaluation of atypical antipsychotics associated rhabdomyolysis using the FDA adverse event reporting system database

Rhabdomyolysis is a potentially fatal adverse reaction mainly caused by certain medications. Few real-world studies have shown a clear association between atypical antipsychotics and rhabdomyolysis. This study aimed to evaluate the association between atypical antipsychotics and rhabdomyolysis using the FDA Adverse Event Report System (FAERS) database. The data were obtained from the FAERS database from January 1, 2004 to December 31, 2023. To identify potential risk signals from the FAERS database, a disproportionality analysis was conducted using the reporting odds ratio (ROR) and corresponding 95% confidence intervals (CIs) with p-values adjusted via Bonferroni correction. The time to onset, hospitalization rate, and mortality of atypical antipsychotics associated rhabdomyolysis were also investigated. A total of 2360 rhabdomyolysis case reports from the FAERS database were considered. Quetiapine had the greatest proportion (27.75%). Olanzapine had the highest positive signal values of rhabdomyolysis. Statistically significant rhabdomyolysis RORs (95% CI) for atypical antipsychotics were (in descending order): olanzapine 4.02 (3.72-4.35), quetiapine 3.81 (0.53-27.6), ziprasidone 2.76 (2.19-3.49), risperidone 2.12 (1.91-2.35), aripiprazole 2 (1.8-2.21), clozapine 1.47 (1.31-1.64). In the time to onset analysis, all atypical antipsychotics associated rhabdomyolysis had early failure type characteristics, the risk of rhabdomyolysis occurrence would be gradually decreased over time. Our study highlights the importance of vigilant patient monitoring following the prescription of atypical antipsychotics to reduce the risk of rhabdomyolysis. It is necessary to monitor serum creatinine kinase (CK) level early, especially during dose adjustment or initiation of new atypical antipsychotics. This research may provide a valuable information for patients, clinicians, and others concerned with the safety of atypical antipsychotics, and optimize clinical practice.