Drug-Induced Anaphylaxis in a Vietnamese Pharmacovigilance Database: Trends and Specific Signals from a Disproportionality Analysis.

Introduction: Despite the numerous studies investigating drug-induced anaphylaxis (DIA), understanding and quantitative data analysis in developing countries remain limited. The aim of our study is to describe and quantify DIA using the National Pharmacovigilance Database of Vietnam (NPDV).
Methods: Spontaneous reporting of adverse drug reactions (ADRs) recorded between 2010 and 2016 were retrospectively analysed to identify DIA reports. The trend and characteristics of DIA cases were described. Multivariate disproportionality analysis was used for signal generation.
Results: Overall, 4873 DIA cases (13.2% of total ADRs) were recorded in the NPDV, 111 of which resulted in death (82% of total ADR-induced deaths) over a 7-year period. There was a remarkable increase in DIA reporting over time (p < 0.001). The incidence rates of DIA reporting per total ADRs and per 100,000 inhabitants remained high (mean rates [95% CI] of 12.06 [9.88-14.24] and 0.77 [0.33-1.20], respectively). Concerning suspected drugs, systemic antibiotics (n = 3318, 68%) were mostly reported with a reporting odds ratio (ROR) and 95% CI of 2.35 [2.20-2.51]. In the case of antibiotic-induced anaphylaxis, the third-generation cephalosporins were predominant (n = 1961, 40.2%, ROR 2.39 [2.24-2.55]). We also noted drugs generally associated with DIA such as contrast agents (ROR 2.43 [2.04-2.88]) and anaesthetics (ROR 4.02 [3.30-4.89]). Furthermore, unexpected signals were observed for alpha-chymotrypsin (ROR 1.75 [1.23-2.44]) and amoxicillin/sulbactam (ROR 1.59 [1.18-2.10]), uncommonly reported in western countries.
Conclusion: In recent years, cases of drug-induced DIA have increased in Vietnam, mostly due to antibiotics and third-generation cephalosporins. The inappropriate use of these drugs should be taken into account. Our findings also highlighted typical Vietnamese signals for alpha-chymotrypsin- and amoxicillin/sulbactam-induced anaphylaxis, which may relate to a specific sociological context in resource-limited countries.