3. Discussion
Our results revealed anaphylaxis in 8.3% of SRsDIAs registered in the AIS “Pharmacovigilance” database (2304/27,727) during the study period 02.04.2019 - 21.0 6.2023. Fatal SRsAs were reported in 9.5% (n - 218). There were close age and sex characteristics in the records of survived and died patients according to the SRsAs analysis (48.2 ± 15.8 years, females - 53.2% vs. 48.0 ± 16.7 years, females - 56.2%).
Based on the results of an 8-year post hoc analysis on the MEREAFaPS Study database (2012–2019) the mean age of population with anaphylaxis was 55.7 ± 17.7 years, and females were 52.4% [
17]. The mean age of patients with drug-induced anaphylaxis in China was determined as 47.6 years (Beijing Pharmacovigilance Database analysis), and 52.7% were females [
18]. Analysis of records with drug-induced anaphylaxis in Poland, West Pomerania, revealed the mean age of population to be 40.5 years, and 54.4% were females [
19]. Female dominance in the structure of patients with drug-induced anaphylaxis (57.9%) was also proved by the results of an analysis of electronic health records (EHRs) of a large United States healthcare system [
11] and by the results of a Tunisian retrospective study (males/female ratio was 0.6)), in the last study patients were younger than in most of other published works: the mean age was 33.52 years [
20]. An analysis of drug-induced anaphylaxis in a Vietnamese Pharmacovigilance Database revealed 51.8% patients between 20 and 60 years old, 53.2% were female [
21]. Korean Health Insurance Review and Assessment Service (HIRA) database analysis (period - January 2011to December 2019) indicated that the mean age of patients with drug-induced anaphylaxis was 52 years, 55.2% were female [
22].
ABs are among the most common triggers of drug-induced anaphylaxis. Their leading role was proved both by retrospective and prospective studies [8, 24, 25]. Our results revealed ABs to be the main cause of anaphylaxis in all age groups (44.6% (n - 1028) in total SRsAs, 42.9% (n - 57) in pediatric SRsAs, and 40.0% (n – 26) in the elderly), and among fatal SRsAs (50% (n - 109)). According to our study the absolute leader among ABs causing anaphylaxis was ceftriaxone.
Zhao Y et al (2018) revealed ABs to be the main group in the structure of drugs involved in anaphylaxis (39.3%), followed by traditional Chinese medicines (11.9%), radiocontrast agents (11.9%), and antineoplastic agents (10.3%) [
18]. Among all the drugs analyzed cephalosporins were leading agents, accounted for 34.5% [
18].
Based on the FDA Adverse Event Reporting System (FAERS) analysis drug-induced anaphylaxis was reported in 0.27% of all adverse drug events (47,496/17,506,002), and causative drugs included ABs (14.87%)), monoclonal antibodies (13.06%), and COX-inhibitors (NSAIDs and acetaminophen – 8.83%). Anaphylaxis deaths were associated with ABs, radiocontrast agents and intraoperative agents, and the rate of fatal cases was 6.28% (2984/47,496) [
23].
Pagani S et al (2022) defined the leading role of ABs in ARs development (53.78%), and penicillins were the most prevalent (66.67%) followed by cephalosporins (21.10%), and fluoroquinolones (8.56%) [
17]. Penicillins were the cause of ARs in 50% according to the data of Wong A et al (2019), and sulfonamides and cephalosporines were other common causes [
9].
Cephalosporins are proved to be common triggers of ARs in adults and children [26 - 29], and a 3rd generation agent including ceftriaxone were among main inducers of allergic reactions reported in hospitals of South Korea [
30]. Analysis of the Korean Adverse Event Reporting System (KAERS) and HIRA database revealed incidence rates for hypersensitivity reactions including anaphylaxis to cefaclor, other 2
nd generation cephalosporins, and 3
rd generation cephalosporins to be 1.17/10,000 persons (0.38/10,000 persons), 3.57/10,000 persons (0.38/10,000 persons), and 5.82/10,000 persons (0.61/10,000 persons), respectively [
31]. Another Korean study revealed five common medication risk factors for drug-induced anaphylaxis including cephalosporine cefaclor, ICCM (iopromide, iohexol, iomeprol), and tolperisone [
22]. Cephalosporines were defined as the most common ABs causing ARs based on the results of China Hospital Pharmacovigilance System analysis [
12]. Third generation cephalosporines were determined as the main cause of drug-induced anaphylaxis based on the results of a Vietnamese Pharmacovigilance Database [
21].
LAs in our study were reported in 20.0% of SRsAs (n - 460). They were ranked second in the list of causative agents among total SRsAs, pediatric SRsAs, and among fatal SRsAs. LAs are typically considered to be anaphylaxis triggers prevalent in dentistry practice [
32], though the risk of true IgE-mediated allergy was shown to be lower than 1% [33 - 37]. Amide local anesthetics are less involved in hypersensitivity reactions compared with ethers, and among amides lidocaine is known to be the most associated with severe allergic reactions. Other amides are safer in this respect, though published data demonstrated their ability to cause anaphylactic shock, that was shown for mepivacaine [
38] and bupivacaine [
39]. French Pharmacovigilance Database System analysis revealed a twentyfold growth of reports on anaphylactic reactions involving local anesthetics from 1985 to 2020 year, and lidocaine was reported to be the most common cause (81.49%) [
40]. Leading role of lidocaine in severe HSRs and in anaphylaxis development in dental practice was stated in the work by Matveev AV et al (2020) [
41]. Anesthetics (first, lidocaine, second – bupivacaine) were reported among top eight pharmacotherapeutic groups involved in anaphylaxis based on results of Vietnamese Pharmacovigilance Database analysis [
21].
NSAIDs are a common cause of hypersensitivity [
25] responsible for a significant proportion of anaphylaxis in clinical practice of tertiary care hospitals and emergency departments [8, 21, 24, 42]. Our data revealed COX-inhibitors (NSAIDs, acetaminophen and metamizole) to be the third causative group among total (10.1%, main drug - acetaminophen) and pediatric SRsAS (6.0%, main drug - acetaminophen), and the fourth - among elderly SRsAs (7.7%, main drug - diclofenac). Fatal SRsAs analysis revealed COX-inhibitors only in 1.8% (two cases - diclofenac, one case - ibuprofen). In the USA NSAIDs (ibuprofen and naproxen) were the second cause of anaphylactic reactions (13.0%) after ABs (61%) [
11], while in Poland NSAIDs were the main causative pharmacological group (acetylsalicylic acid, ketoprofen, metamizole and ibuprofen) [
19]. These results are supported by the FAERS database analysis (study period 1999 to 2019) by Yu RJ et al (2021), which revealed acetaminophen and NSAIDs (acetylsalicylic acid, celecoxib, diclofenac) among top 50 drugs causing anaphylaxis [
23]. Based on the analysis of a Vietnamese Pharmacovigilance Database NSAIDs were found to be a second pharmacological group involved in drug-induced anaphylaxis [
21]. Published data indicate that in children NSAIDs are a second significant pharmacological group causing anaphylaxis after ABs [
43]. Our results revealed acetaminophen to be the leader among COX-inhibitor in total SRsAs and pediatric SRsAs., and no fatal cases involving acetaminophen were detected. EudraVigilance Database analysis (2007–2018) found that acetaminophen-induced anaphylaxis was most common at age group 18–64 years, and among acetaminophen-induced ARs anaphylaxis was the second cause of death after hepatic failure with shock [
44]. A systematic review of 85 studies reporting hypersensitivity reactions to acetaminophen revealed that acetaminophen hypersensitivity reaction prevalence among children was 10.1% (95% confidence interval 4.5-15.5) [
45]. A retrospective analysis of 159 validated spontaneous reports in children (database of German Federal Institute for Drugs and Medical Devices) revealed another COX-inhibitor, ibuprofen, to be the main drug responsible for anaphylaxis development [
46].
According to our results ICCM were identified in 6.6% of SRsAs (n - 153), with the most common agents iopromide and iohexol. ICCM were on the third place among causative drugs in the elderly SRsAs (12.3%). This group of agents is known to mediate severe hypersensitivity reactions which may lead to a lethal outcome [47, 48]. ICCM group was reported to be a leader among drugs involved in anaphylaxis due to the results of 13-year period analysis of Japanese Adverse Drug Event Report (JADER) database [
49]. Based on the results of a 10-year study in China, total radiocontrast agents accounted for 11.9%, ICCM - for 9.5% [
18]. Pagani S et al (2022) demonstrated association of anaphylaxis with radiology contrast agents in 6.92% [
17]. Nguyen KD et al (2019) reported contrast media to be on the fourth place among all pharmacological groups caused drug-induced anaphylaxis [
21]. FAERS database analysis reported iohexol, iopamidol and iopromide among top 50 drugs involved in anaphylaxis [
23]. Published studies suggest that anaphylaxis due to radiocontrast medium is more common in older age and on repeated drug exposure [
50].
Our study reported CV-drugs to be the fourth significant group involved in anaphylaxis in total SRsAs (6.2%, n - 143) with next most common groups: ACEIs (enalapril, captopril, perindopril), beta-blockers (bisoprolol, metoprolol, atenolol), and calcium channel blockers (nifedipine, amlodipine, verapamil). In the elderly CV-drugs were the second group caused anaphylaxis (20%, n - 13). ACEIs and beta-blockers are known causes of anaphylaxis in clinical practice [
51]. A systematic review and meta-analysis of observational studies stated that beta-blockers and ACEIs increase the severity of anaphylaxis (beta-blockers, odds ratio [OR] 2.19, 95% confidence interval [CI] 1.25-3.84; ACEIs, OR 1.56, 95% CI 1.12-2.16) [
52]. Anaphylaxis severity was shown to be increased with ACEIs intake along with presence of such factors as mastocytosis, and high fever prior to anaphylaxis [
53]. Published studies based on pharmacovigilance databases revealed less significance of CV-drugs in anaphylaxis compared with our results. FAERS analysis reported no CV-agents among top-50 drugs causing anaphylaxis [
23]. Vietnamese Pharmacovigilance Database analysis revealed cardiac therapy agents on the 22nd place among drugs involved in anaphylaxis [
21], a 10 year retrospective analysis of the Beijing Pharmacovigilance Database reported cardiovascular medications accounted for 0.9% of drug-induced anaphylaxis [
18].
The total number of SRsAs with causative agents being CNS-active drugs in our study was 35 (1.5%) with the leading role of fentanyl, diazepam, and tramadol. Published clinical studies revealed relatively low incidence of fentanyl-associated anaphylaxis [54, 55], mainly cases are reported [56 - 59]. Low frequency of anaphylaxis is also known for benzodiazepines [
60], though diazepam is considered to be more common cause of allergy compared with midazolam [
61]. Pagani S et al (2022) indicated a frequency of anaphylaxis due to tramadol equal to 0.32%, 2/608 [
17], and literature analysis revealed only several cases of tramadol-induced anaphylaxis [62 - 64]. From the other hand, some studies based on pharmacovigilance database analysis revealed a significant role for several drugs affecting CNS. FAERS database analysis reported fentanyl, midazolam, propofol, and sufentanyl among top-50 drugs involved in anaphylaxis [
23], Vietnamese Pharmacovigilance Database analysis indicated analgesic opioids and psychostimulants were on the 18
th and 19
th positions among groups involved in anaphylaxis [
21].
NMBAs in our study accounted for 1.43% (n - 33), and the most prevalent were rocuronium and suxamethonium. NMBAs are the most frequent allergens responsible for acute hypersensitivity reactions during anaesthesia [65 - 67], and leading causative agents for perioperative anaphylaxis [
68]. A French pharmacovigilance survey from 2000 to 2012 revealed suxamethonium and rocuronium to be the most common NMBAs causing ARs [
69]. Atracurium, rocuronium, and succinylcholine were listed among top 50 drugs involved in anaphylaxis based on FAERS analysis [
23].
According to fatal SRsAs analysis most of cases were due to ABs (and beta-lactams among ABs), which is in complete accordance with published data. Beta-lactam antibiotics, muscle relaxants, and injected radiocontrast medium were the main triggers of fatal drug anaphylaxis based on analysis made by Turner PJ et al (2017) [
70] and the higher prevalence of ABs among drugs involved in total ARs and fatal ARs is also proved by the vast majority of reported studies in adults and children [11, 17, 18, 23, 43, 71, 72].
Published data indicate that drug-induced anaphylaxis is associated with more lethal cases than food-induced and venom-induced [
73]. Actuality of the problem is supported by increasing number of fatal cases reported in modern studies. A systematic review of 46 observational studies reported increased frequency of deaths due to drug-induced anaphylaxis during the study period (IRR per year, 1.02; 95% CI, 1.00-1.04), and the highest rates were detected for Australian region [
74]. Jerschow E et al (2014) stated a significant increase in fatal drug-induced anaphylaxis over 12 years (from 0.27 (95% CI, 0.23-0.30) per million in 1999 to 2001 to 0.51 (95% CI, 0.47-0.56) per million in 2008 to 2010 (p< 0.001) [
75]. Fatal SRsAs percentage reported in our study (9.5%) exceeds published values. FAERS database analysis revealed 6.28% (2,984/47,496) reports of anaphylaxis followed by death [
23], Brazilian Hospital Information System – 5.8% [
76], Beijing Pharmacovigilance Database – 3.3% (39/1,189) [
18], Vietnamese Pharmacovigilance Database analysis - about 2.3% (111/4,873) [
21]. The rate of fatal drug-induced anaphylaxis in Spain was 1.02% [
77], and Latin American anaphylaxis registry revealed that only 0.3% of cases were fatal [
78].
Our study has some limitations. First, retrospective design of the study based on the analysis of SRsAs entered in the AIS “Pharmacovigilance” made it impossible to evaluate the effect of concomitant medications and comorbidities, laboratory tests performed, and to estimate risks of anaphylaxis in different populations.
It is worth to note, that the number of SRsAs reported in our study was based on the analysis of spontaneous reporting records and thus cannot completely reflect the prevalence of anaphylaxis in a real clinical practice. Reported proportions of drugs involved in anaphylaxis described in our study may be determined not by their true safety profile, but by a frequency of their prescribing. E.g.: an absolute leader determined in our study was ceftriaxone, and it is one of the most prescribed drugs to treat various infectious diseases worldwide, ranging from 2.5% of therapeutic prescriptions in Northern Europe to 24.8% in Eastern Europe; also it is the most prescribed AB for a surgical prophylaxis (34.4% of ABs prescriptions in Eastern Europe, 24.8% in Southern Europe, 23.6% in West and Central Asia, and 19.7% in Northern Africa) [
79]. A promising approach to assess real world prevalence of ARs due to a drug may be based on a parallel assessment of a drug consumption rates.