Hypersensitivity reactions to non-steroidal anti-inflammatory drugs (NSAIDs) - a retrospective study

Hypersensitivity reactions to nonsteroidal anti-inflammatory drugs: does age matter?

Background: Nonsteroidal anti-inflammatory drugs (NSAIDs) are reported to be the leading cause of drug hypersensitivity reactions. The aim of this study was to characterize a cohort of patients with NSAID hypersensitivity and establish if there are any differences between two groups of adult patients, under 55 years old and over 55 years old, and identify safe alternative options. Methods: Patients with NSAID hypersensitivity who were referred to a single tertiary Allergy center from January 2019 to December 2021 were included. Clinical information was obtained from a review of medical records. Results: A total of 135 patients with a history of NSAID-induced hypersensitivity reactions were included, 80 patients under 55 years old and 55 patients older than 55. Most of the patients enrolled were female (80.74%) and the mean age was 50.21 years, ranging from 18 to 78 years old. The time interval between the first reaction and the allergy work-up was longer in the older group (average timeframe 6.87 years) than in the younger group (average timeframe 3.77 years). The main culprit was metamizole in both groups. An oral provocation test to paracetamol was performed in most of the patients who tolerated the intake of 1000 mg, except for 2 patients who developed angioedema. Conclusion: Angioedema was the most encountered symptom in our population. Age does not influence the allergy work-up of patients with a history of NSAID-induced hypersensitivity reactions. The drug provocation challenge remains the gold standard for finding a suitable alternative in patients with NSAID-induced hypersensitivity.

Lack of Major Involvement of Common CYP2C Gene Polymorphisms in the Risk of Developing Cross-Hypersensitivity to NSAIDs

Cross-hypersensitivity to non-steroidal anti-inflammatory drugs (NSAIDs) is a relatively common, non-allergic, adverse drug event triggered by two or more chemically unrelated NSAIDs. Current evidence point to COX-1 inhibition as one of the main factors in its etiopathogenesis. Evidence also suggests that the risk is dose-dependent. Therefore it could be speculated that individuals with impaired NSAID biodisposition might be at increased risk of developing cross-hypersensitivity to NSAIDs. We analyzed common functional gene variants for CYP2C8, CYP2C9, and CYP2C19 in a large cohort composed of 499 patients with cross-hypersensitivity to NSAIDs and 624 healthy individuals who tolerated NSAIDs. Patients were analyzed as a whole group and subdivided in three groups according to the main enzymes involved in the metabolism of the culprit drugs as follows: CYP2C9, aceclofenac, indomethacin, naproxen, piroxicam, meloxicam, lornoxicam, and celecoxib; CYP2C8 plus CYP2C9, ibuprofen and diclofenac; CYP2C19 plus CYP2C9, metamizole. Genotype calls ranged from 94 to 99%. No statistically significant differences between patients and controls were identified in this study, either for allele frequencies, diplotypes, or inferred phenotypes. After patient stratification according to the enzymes involved in the metabolism of the culprit drugs, or according to the clinical presentation of the hypersensitivity reaction, we identified weak significant associations of a lower frequency (as compared to that of control subjects) of CYP2C8*3/*3 genotypes in patients receiving NSAIDs that are predominantly CYP2C9 substrates, and in patients with NSAIDs-exacerbated cutaneous disease. However, these associations lost significance after False Discovery Rate correction for multiple comparisons. Taking together these findings and the statistical power of this cohort, we conclude that there is no evidence of a major implication of the major functional CYP2C polymorphisms analyzed in this study and the risk of developing cross-hypersensitivity to NSAIDs. This argues against the hypothesis of a dose-dependent COX-1 inhibition as the main underlying mechanism for this adverse drug event and suggests that pre-emptive genotyping aiming at drug selection should have a low practical utility for cross-hypersensitivity to NSAIDs.