Cyclooxygenase selectivity and chemical groups of non-steroidal anti-inflammatory drugs and the frequency of reporting hypersensitivity reactions: a case/non-case study in VigiBase

The reporting of hypersensitivity reactions (HSRs) among non-steroidal anti-inflammatory drugs (NSAIDs) according to cyclooxygenase (COX) selectivity and chemical groups has not been published yet in one study. This study assessed the reporting frequency of HSRs for NSAIDs based on their relative inhibitory potency towards COX enzymes and chemical groups, including the presence/absence of a functional sulfonamide group, in strata of 5 years after market authorization. A case/non-case study was performed among Individual Case Safety Reports (ICSRs) with NSAIDs as suspected drugs in VigiBase, the WHO spontaneous reporting database. Cases were ICSRs mentioning angioedema and anaphylactic/anaphylactoid shock conditions, while non-cases were ICSRs without HSRs. NSAIDs were categorized into (i) NSAIDs with highly COX-2 selectivity (coxibs), (ii) Non-coxib NSAIDs with COX-2 preference, (iii) NSAIDs with poor selectivity, or (iv) NSAIDs with unknown selectivity. Chemical groups were defined based on the Anatomical Therapeutic Chemical classification system and the presence/absence of a functional sulfonamide group. Reporting odds ratios (RORs) and 95% confidence intervals (95% CIs) were calculated using logistic regression analysis. We identified 13,229 cases and 106,444 non-cases. In the first 5 years after marketing, poor selectivity NSAIDs and acetic acid derivatives were associated with the highest ROR of HSRs (age- and sex-adjusted ROR 2.12, 95%CI: 1.98-2.28 and ROR 2.21, 95%CI: 1.83-2.66, respectively), all compared to coxibs, and also sulfonamide NSAIDs compared to non-sulfonamide NSAIDs (age- and sex-adjusted ROR 1.38, 95%CI: 1.29-1.47). After the first 5 years of marketing, most of the RORs returned to approximately 1. This article is protected by copyright. All rights reserved.