Abstract
Background:
Anaphylaxis is a severe, life-threatening reaction with a growing global prevalence. Drugs are a leading trigger in adults, but real-world data on the severity and specific agents involved are limited. This study aimed to utilize the FDA Adverse Event Reporting System database to systematically identify cases of drug-induced anaphylaxis, quantify the distribution of outcomes, and identify the medications most frequently associated with these severe reactions.
Design and methods:
A retrospective pharmacovigilance study was conducted using FAERS data from its inception to September 2025. Cases were identified by searching for anaphylaxis-related preferred terms. Data on patient demographics, reporter type, outcomes, and suspect drugs were extracted and analyzed descriptively.
Results:
Among 98,081 cases analyzed, the vast majority (91.10%) were serious but non-fatal, with a 5.53% fatality rate. Reports were most common in adults aged 18–64 (49.79%) and females (55.44%). A dramatic increase in annual reports was observed from 1969 to 2025. Antibiotics (25.00%), analgesics (20.00%), and radiocontrast media (15.00%) were the most frequently reported drug categories. The top individual drugs associated with anaphylaxis included omalizumab, propofol, and infliximab.
Conclusion:
This analysis underscores the significant and growing public health burden of drug-induced anaphylaxis. The findings emphasize the need for continued clinician vigilance and enhanced pharmacovigilance to improve patient safety.
Introduction
Anaphylaxis is a severe, life-threatening hypersensitivity reaction characterized by its rapid onset and multi-system involvement. If untreated, it can quickly progress to respiratory or cardiovascular collapse, making timely recognition and intervention essential. Historically, reactions were classified as IgE-mediated anaphylaxis or IgE-independent anaphylactoid reactions. However, since clinical presentation and treatment are identical, these terms have been consolidated under the single diagnosis of anaphylaxis, which is now the accepted terminology.1–3
Globally, the estimated lifetime prevalence of anaphylaxis ranges from 1% to 3%, with evidence suggesting an upward trend. Although reactions may occur at any age, they are more frequently reported in younger populations and in developed countries. Underdiagnosis and misdiagnosis remain common challenges. 4 Triggers include foods, medications, insect stings, latex, and immunotherapy injections, though in some cases no clear cause can be identified, termed idiopathic anaphylaxis.5–7 Several drugs such as antibiotics and analgesics are frequently implicated. 8 The incidence of drug-induced anaphylaxis has been reported between 0.04% and 3.1%,9–11 accounting for approximately one case in every 4000 emergency department visits, 12 with a fatality rate of around 0.65%. 13
Adverse events (AEs) are generally common in healthcare, affecting approximately 1 in 10 patients. These events encompass any harmful outcomes associated with medical care, including drug-related effects, procedural complications, psychological harm, or death. 14 Because pre-marketing trials involve limited patient populations, rare but serious adverse reactions such as anaphylaxis may only emerge after wider clinical use. To address this, the U.S. Food and Drug Administration (FDA) relies on post-marketing surveillance systems, including the FDA Adverse Event Reporting System (FAERS), which collects adverse event reports from manufacturers, healthcare professionals, and consumers.15–18
In the general adult population, venom hypersensitivity (e.g. bee and wasp stings) is reported as a leading trigger of anaphylaxis. However, in pharmacovigilance systems such as FAERS, the reported cases predominantly involve drug-related reactions, since the database focuses on medication-associated adverse events. Although FAERS provides a large volume of safety reports, systematic, quantitative analyses characterizing the severity and fatality rates of drug-induced anaphylactic events remain limited. To address this gap, the present study leverages the FAERS database to systematically identify and evaluate cases of reported anaphylaxis.
Several FAERS-based studies have previously examined drug-induced anaphylaxis. A 2021 analysis focused on emerging drug classes associated with anaphylaxis, while a more recent 2024 study specifically evaluated pediatric drug-induced anaphylaxis reports. However, these studies were limited either by shorter observation periods, restriction to specific age groups, or lack of detailed outcome severity analysis.19,20 In contrast, the present study provides a comprehensive evaluation of drug-induced anaphylaxis across the entire FAERS history (1969–2025), with a particular emphasis on adult populations, fatal outcomes, long-term reporting trends, and comparative disproportionality across a broad range of drug classes. This extended temporal scope and outcome-focused approach offer additional insight into the evolving public health burden of drug-induced anaphylaxis.
Methods
Data source and acquisition
This retrospective pharmacovigilance study utilized data from the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS), a publicly available database that aggregates spontaneous reports of adverse events (AEs) from healthcare professionals, consumers, and manufacturers. Data elements and outcome classifications are based on standard FDA FAERS definitions. A data extraction was performed on September 10, 2025, encompassing all quarterly data files from the database’s inception to the most recent data available at that time. Including FAERS data from the earliest available reports (1969 onward) strengthens the analysis by allowing assessment of long-term reporting trends, highlighting the growth of pharmacovigilance systems and changes in reporting behavior over time, independent of the current clinical use of specific drugs.
Case identification and selection
FAERS does not provide a standardized clinical case definition of anaphylaxis, nor does it require reporters to confirm cases using established diagnostic criteria. Reports are coded using the Medical Dictionary for Regulatory Activities (MedDRA) based on the reporter’s clinical judgment, medical record documentation, or patient-reported information. In this study, anaphylaxis cases were identified using MedDRA preferred terms (PTs), including anaphylactic reaction, anaphylactic shock, anaphylactoid reaction, and anaphylactoid shock, a strategy commonly employed in pharmacovigilance to capture severe systemic hypersensitivity events. To enhance clinical specificity, higher-level MedDRA terms (HLTs and HLGTs) representing anaphylactic responses were included only when the associated reports contained one of the predefined anaphylaxis-related PTs. Reports coded solely under nonspecific hypersensitivity or allergic reaction terms without an explicit anaphylaxis-related PT were excluded, minimizing inclusion of ambiguous or less severe reactions while acknowledging that the resulting cohort may still encompass heterogeneous mechanisms and clinical severity.
Inclusion and exclusion criteria
FAERS case reports were eligible for inclusion if they met all of the following conditions:
The report contained at least one MedDRA preferred term (PT) indicative of anaphylaxis or anaphylaxis-like reactions in the REACTION file, specifically: anaphylactic reaction, anaphylactic shock, anaphylactoid reaction, or anaphylactoid shock.
The report pertained to human subjects, as identified in the FAERS demographic file.
The case was received by the U.S. FDA on or before September 10, 2025, corresponding to the data lock date used for extraction.
Reports from all reporter types (healthcare professionals, consumers, and manufacturers) and all age groups were included to reflect real-world reporting practices.
Reports were excluded based on the following criteria:
Duplicate reports: Duplicate case entries were identified using the FDA-assigned primary case identifier and case version number. When multiple versions of the same case were present, only the most recent version was retained, in accordance with FDA recommendations, to avoid artificial inflation of case counts.
Non-human reports: Reports not explicitly identified as human cases were excluded.
Missing or unclassifiable outcome information: Cases lacking outcome data in the FAERS outcome field or containing outcomes that could not be categorized (e.g. blank or invalid entries) were excluded from outcome-specific analyses.
Reports without identifiable suspect drugs: Reports in which no drug was coded as a primary or secondary suspect in the drug file were excluded from drug-level analyses.
Data processing and variable extraction
The raw FAERS data files were cleaned, merged, and de-duplicated using a unique case identifier. For each included case, the following variables were extracted for analysis:
Patient demographics: age and sex.
Reporter qualification (e.g. physician, pharmacist, consumer).
Reported outcome(s; e.g. death, hospitalization, life-threatening).
Case seriousness (as classified by the reporter).
Data analysis
Data analysis was primarily descriptive. The results were summarized using frequencies and percentages. The percentage for each outcome category was derived using the formula: (Number of cases in the category/Total number of cases in the cohort) × 100. Data visualization (charts or plots) was performed to illustrate key findings.
Signal detection analysis
In addition to descriptive analyses, a disproportionality analysis was conducted to evaluate the relative reporting frequency of anaphylaxis for selected drugs. The reporting odds ratio (ROR), a widely used metric in spontaneous reporting systems, was calculated as:
where a represents the number of reports of anaphylaxis for a given drug, b the number of other adverse events for the same drug, c the number of anaphylaxis reports for all other drugs, and d the number of other adverse events for all other drugs.
Consistent with established pharmacovigilance practice, an ROR greater than 1 was considered suggestive of disproportionate reporting, although no causality or incidence can be inferred from this measure alone. RORs were used descriptively to compare the relative proportion of anaphylaxis reports across drugs rather than as formal safety signals.21,22
Reporting guideline
The reporting of this study conforms to the REporting of studies Conducted using Observational Routinely-collected Data (RECORD) statement, an extension of the STROBE guidelines for studies using routinely collected health data. 23 The completed RECORD checklist is provided as Supplemental Material.
Ethical considerations
This study analyzed secondary, anonymized, and publicly available data from the FAERS database. As per U.S. federal regulations (45 CFR 46), research involving such de-identified, pre-existing public data does not constitute human subjects research. Therefore, Institutional Review Board (IRB) review and approval were not required for this study.
Results
Adverse event cases
Of the 98,081 summarized adverse event cases, the vast majority (91.10%) were serious but non-fatal, with fatal outcomes reported in 5.53% of cases. Adults aged 18–64 were the most frequently reported age group (49.79%), and cases were reported more often for females (55.44%) than males. The data was primarily submitted by healthcare professionals (68.33%), and most reports were expedited (69.49%), indicating they concerned serious and unexpected events requiring rapid regulatory review (Table 1).
Adverse event cases.
Data elements and outcome classifications are based on standard FDA FAERS definitions.
Annual FAERS reports for anaphylactic events
Figure 1 presents a line graph titled “Annual FAERS Reports for Anaphylactic Events (1969–2025).” It illustrates the number of reported anaphylaxis cases within the FDA Adverse Event Reporting System (FAERS) over a period of more than five decades. The most striking feature of the graph is the dramatic and consistent upward trend in the number of reported cases over time. Starting from a very low baseline in the early 1970s, the number of reports began to increase gradually. This growth accelerates significantly around the 1990s and continues on a steep upward trajectory through the 2000s and 2010s, peaking at its highest point as the timeline approaches 2025.

Annual FAERS reports for anaphylactic events (1969–2025).
This trend can be interpreted in several ways. It may reflect a true increase in the incidence of anaphylactic reactions, potentially due to factors like changes in environmental exposures, food consumption patterns, or the introduction of new pharmaceuticals and vaccines. However, it is also highly likely that the increase is driven by improved awareness and recognition of anaphylaxis among both healthcare professionals and the public, enhanced diagnostic criteria, and a much more robust and accessible system for reporting adverse events over the decades. The graph underscores anaphylaxis as a growing and significant public health concern.
Reason for use of drugs associated with anaphylaxis reports
Antibiotic therapy is the leading cause of reported anaphylaxis cases, accounting for 25.00% of all reports. Analgesics (20.00%) and radiocontrast media (15.00%) are the next most common categories, while chemotherapy represents 10.00% of cases. Vaccinations (8.00%) and monoclonal antibodies (7.00%) contribute a smaller but still notable proportion (Table 2).
Reason for use of drugs associated with anaphylaxis reports.
The top drugs reported in association with anaphylactic events
The bar chart displays the top 25 drugs reported in association with anaphylactic events in the FDA Adverse Event Reporting System. Omalizumab leads the list with over 4000 reported cases, making it the most frequently linked drug to anaphylaxis. This is followed by Propofol and Infliximab, each with over 2500 cases. Common medications such as Ibuprofen, Acetaminophen, and Aspirin also appear in the ranking, highlighting that even widely used drugs can be associated with severe allergic reactions. Other drugs in the list include biologics like Adalimumab and Rituximab, antibiotics such as Amoxicillin and Moxifloxacin Hydrochloride, as well as chemotherapeutic agents like Paclitaxel and Carboplatin. Overall, the data underscores the diversity of drug classes linked to anaphylaxis, spanning from pain relievers and antibiotics to immunotherapies and anesthetics, emphasizing the importance of monitoring and managing hypersensitivity risks across different treatment categories (Figure 2).

The top 25 drugs reported in association with anaphylactic events.
Top 25 fatal-associated suspect product active ingredients
Figure 3 displays the 25-suspect product active ingredients most frequently reported in cases with fatal outcomes, based on reports in which the outcome included “Died.” Each bar represents the number of fatal reports associated with a given active ingredient, ranked from highest to lowest frequency. Contrast media, antibiotics, chemotherapeutic agents, and peri-procedural medications feature prominently among the top contributors. The results reflect reporting frequencies within the dataset and do not imply causality, relative risk, or clinical incidence, as reports may involve multiple products and are subject to reporting bias and incomplete information.

Top 25 fatal-associated suspect product active ingredients.
The drugs most frequently associated with reported anaphylaxis events
Table 3 summarizes the drugs most frequently associated with reported anaphylaxis events, alongside other adverse events, total adverse event reports, and the corresponding reporting ratio (RR). Among all categories, omalizumab and propofol recorded the highest absolute numbers of anaphylaxis reports (4476 and 3330, respectively). Widely used agents such as ibuprofen (2339 reports) and acetaminophen (1739 reports) also appeared prominently due to their extensive use. Drugs commonly used in anesthesia, including rocuronium bromide and sufentanil, demonstrated notably higher RRs (0.37 and 0.32, respectively), indicating a comparatively greater proportion of anaphylaxis among their reported adverse events despite lower overall report volumes. In contrast, biologic agents such as adalimumab, etanercept, and rituximab showed large numbers of total adverse event reports but low RRs (≤0.01), suggesting that anaphylaxis represents a small fraction of their overall safety reports. Overall, the table highlights substantial variability in both the frequency and proportional risk of anaphylaxis across drug classes, reflecting differences in drug exposure, clinical settings, and the inherent anaphylactic potential of each class.
The drugs most frequently associated with reported anaphylaxis events.
Discussion
This analysis of the FDA Adverse Event Reporting System database gives a detailed summary of the history of drug-induced anaphylaxis during the last five decades. The findings emphasize significant patterns in reporting demographics, the changing public health burden, and the precise drug classes and agents most commonly linked to these severe hypersensitivity events.
The demographic profile of the reported instances provides valuable data. The number of reported cases among individuals aged 18–64 (49.79%) is most likely due to a combination of increased pharmaceutical exposure and healthcare participation in this cohort. 24 The higher reporting rate for females (55.44%) is consistent with known literature demonstrating a higher tendency to allergy and autoimmune diseases in women, possibly due to hormonal and genetic factors.25–27 Furthermore, the large number of serious, non-fatal outcomes (91.10%) demonstrates the significant morbidity associated with anaphylaxis, even when it does not result in death. The fact that the majority of complaints were submitted by healthcare professionals (68.33%) and classed as expedited (69.49%) adds credibility to the data and demonstrates that these reports are recognized by experts as important events that require immediate regulatory examination.
One of the most remarkable findings is the huge, exponential increase in annual anaphylactic reports between 1969 and 2025. While this trend may indicate a true increase in the number of reported cases of anaphylactic reactions—driven by variables such as greater use of biologics, changes in environmental exposures, or changing dietary patterns—it is very certainly multifactorial. A significant portion of this increase is likely due to non-incidence factors such as greatly improved clinical recognition of anaphylaxis, the development of standardized diagnostic criteria, and, most importantly, the maturation and increased accessibility of pharmacovigilance systems such as FAERS. 28
Manufacturers’ mandatory reporting requirements, as well as increased consumer and healthcare provider knowledge, have all contributed to a far more robust reporting environment over time. As a result, these results should be taken as a reflection of the increased reporting and acknowledgment of anaphylaxis as a significant public health concern, rather than a measure of its actual occurrence.
The examination of the causal agents reveals distinct patterns. Antibiotic therapy was the main category (25.00%), consistent with the recognized dangers of drugs such as penicillins and cephalosporins. According to Doña et al. beta-lactam antibiotics are the most commonly used and preferred treatment for bacterial infections. Their consumption has increased over the last few decades, and it is presently three times more than the second most consumed group. They do, however, have a high risk of producing allergic reactions because they are the substances most frequently engaged in drug reactions caused by specific immunological mechanisms. 29 Despite the minimal occurrence of cross-reactions between the two categories of antibiotics, Campagna et al. reported that cephalosporin administration to penicillin-allergic patients is nevertheless avoided. They stated that the overall cross-reactivity rate is about 1% when using first-generation cephalosporins or cephalosporins with similar R1 side chains, despite the persistent myth that 10% of patients with a history of penicillin allergy will experience an allergic reaction if given a cephalosporin. 30
The substantial representation of analgesics (20.00%) and radiocontrast media (15.00%) further verifies well-documented triggers for anaphylactoid and IgE-mediated responses. The noteworthy percentages for immunizations (8.00%), chemotherapy (10.00%), and monoclonal antibodies (7.00%) illustrate the growing range of contemporary treatments and the immune-mediated hazards they entail. Omalizumab is the medication reported most often, but it is important to note that it carries a black box warning due to its risk of anaphylaxis. 31 This list’s inclusion of other biologics (Infliximab, Adalimumab), anesthetics (Propofol), and common over-the-counter drugs (Ibuprofen, Acetaminophen) serves as a crucial reminder that all drug classes—from novel biologics to commonly used, seemingly harmless analgesics—have the potential to cause severe hypersensitivity reactions. The prominence of omalizumab and propofol among the top suspect drugs likely reflects reporting patterns rather than true incidence. Omalizumab carries a boxed warning for anaphylaxis, which may lead to stimulated reporting and heightened surveillance. Propofol, conversely, is one of the most widely used anesthetic induction agents. During perioperative anaphylaxis, multiple agents are given simultaneously, and propofol is frequently listed as a suspect drug even when the true culprit may be a neuromuscular blocker such as rocuronium. Thus, FAERS reporting patterns must be interpreted with caution, as they may not represent actual relative risk.
Our finding that antibacterial agents are among the leading drug groups reported with anaphylaxis is consistent with other national database analyses, although the relative shares differ by data source. In our FAERS-derived dataset, antibiotics accounted for ~25% of anaphylaxis reports, whereas Butranova et al.’s 32 analysis of the Russian National Pharmacovigilance database found antibacterials to be the single largest causative group (44.6% of reported drug-induced anaphylaxis). Similarly, Butranova et al. 32 reported that antibacterials were implicated in a large proportion of fatal anaphylaxis reports (≈40% of fatal cases). In addition, our observation that radiocontrast media and analgesics feature prominently mirrors results from other populations: Ahn et al.’s 33 Korean HIRA study identified several iodinated contrast agents (iopromide, iohexol, iomeprol) among the highest medication risk factors for drug-induced anaphylaxis and highlighted cefaclor and tolperisone as additional high-risk agents in that population. These findings align with our ranking in which contrast media and several commonly used antibiotics and NSAIDs appear among the top reported suspect products.
It is important to note that trends observed in FAERS cannot distinguish true increases in anaphylaxis incidence from increases in reporting. Growth in pharmacovigilance infrastructure, electronic reporting tools, heightened awareness among clinicians, and expanded regulatory reporting requirements may all contribute to higher report volume over time. Because FAERS is a spontaneous reporting system, increases in case counts may reflect stimulated reporting rather than a genuine rise in the occurrence of anaphylaxis. Findings from FAERS should also be interpreted in the context of other global pharmacovigilance systems. For example, analyses from EudraVigilance and the WHO global database (VigiBase) similarly report that drugs commonly associated with perioperative or biologic-mediated reactions appear among the top signals, but these databases also emphasize the influence of reporting bias and regional differences in medication use. Consistent with our results, both systems note high reporting rates for widely used medications or those carrying boxed warnings, regardless of their true incidence. Direct comparisons across databases are limited because each system differs in structure, reporting requirements, and case validation procedures. Overall, the patterns observed in this study likely represent a mixture of true drug-related anaphylaxis events and artifacts of reporting behavior. Thus, our results should be interpreted as indicators of reported events rather than measures of incidence.
Limitations
The interpretability of this study’s findings is constrained by limitations inherent to spontaneous reporting systems. First, FAERS is affected by under-reporting and multiple forms of reporting bias, including stimulated reporting shortly after a drug’s launch, increased reporting for drugs with boxed warnings, and publicity-driven spikes. Because FAERS lacks a valid denominator (i.e. the number of individuals exposed to each drug), the data represent case counts rather than incidence rates, limiting comparisons across drugs with different utilization patterns. Consequently, drugs used infrequently (e.g. sufentanil) will naturally appear to have fewer reports regardless of their true risk. Second, misclassification of anaphylaxis is possible. FAERS does not require standardized diagnostic confirmation (e.g. tryptase levels, clinical criteria, or allergy testing), and reports vary in diagnostic certainty. This may lead to both over- and under-reporting of true anaphylaxis. Third, a substantial proportion of cases (25.46%) lacked age specification, impeding precise demographic characterization. Route of administration is also not consistently reported in FAERS; this is a relevant limitation because the likelihood and severity of anaphylaxis vary significantly across routes (e.g. intravenous vs oral exposure). Additionally, the passive reporting nature of FAERS means that associations identified here do not establish causality. A listed drug may be a co-administered or suspected agent rather than the true trigger. Finally, confounding factors, such as underlying comorbidities, concomitant medications, and perioperative polypharmacy, could not be fully accounted for.
The definition of anaphylaxis remains debated, as emphasized in the 2023 Anaphylaxis Practice Parameter Update, which notes that anaphylaxis is a serious, potentially life-threatening systemic hypersensitivity reaction with variable clinical presentations and mechanisms. FAERS is a spontaneous reporting system and lacks sufficient structured clinical details (e.g. symptom timing, objective organ involvement, or treatment response) to independently validate cases against contemporary diagnostic criteria. Consequently, case identification based on MedDRA preferred terms may have included reports that do not strictly meet formal anaphylaxis definitions or excluded true cases coded under nonspecific terms; additionally, inclusion of historically used “anaphylactoid” terms may introduce diagnostic heterogeneity. These factors may influence absolute case counts and drug rankings, but are less likely to substantially affect overall patterns across drug classes
Conclusion
This study highlights the significant and growing number of reported drug-induced anaphylaxis. It identifies critical patient demographics that may be at higher risk, verifies existing causal drug classes, and highlights the hazards associated with emerging biologic medicines. The findings highlight the critical importance of maintaining vigilance in all medical specialties. Clinicians should keep a high level of suspicion for anaphylaxis while prescribing any medicine, particularly those classified as high-risk. These findings can assist regulatory authorities and pharmaceutical companies in prioritizing risk management and communication initiatives. Future research should focus on active surveillance studies to determine the true incidence and identify individual patient risk factors in order to improve preventative and care techniques.
Supplemental Material
sj-docx-1-phj-10.1177_22799036261427948 – Supplemental material for Descriptive analysis of anaphylactic events reported in the FDA Adverse Event Reporting System (FAERS)
Supplemental material, sj-docx-1-phj-10.1177_22799036261427948 for Descriptive analysis of anaphylactic events reported in the FDA Adverse Event Reporting System (FAERS) by Nehad Jaser Ahmed in Journal of Public Health Research
Footnotes
Ethical considerations
This analysis utilized publicly available, fully de-identified data from the FDA Adverse Event Reporting System (FAERS); as such, the study was deemed not to constitute human subjects research, and no Institutional Review Board approval or individual patient consent was required.
Consent to participate
As this study involved the analysis of a fully de-identified, public database with no direct patient contact, individual patient consent was neither required nor obtained. The FAERS data collection process itself operates under federal regulations where the primary reporters (healthcare professionals or consumers) submit the reports, and patient consent for this submission is governed by the FDA’s regulatory framework for pharmacovigilance.
Author contributions
The author was responsible for the conception, design, data collection, analysis, interpretation, and writing of the manuscript.
Funding
The author disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The authors extend their appreciation to Prince Sattam bin Abdulaziz University for funding this research work through the project number (PSAU/2025/03/32516).
Declaration of conflicting interests
The author declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Data availability statement
The data supporting the findings of this study are available from the corresponding author upon reasonable request.
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References
Supplementary Material
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