Epidemiology of anaphylaxis: A retrospective cohort study in Taiwan

Objective: Medication-induced anaphylaxis is a potentially fatal event. Little is known at present about the patterns of medication-induced anaphylaxis in Asian countries. The current study aims to examine the pattern of documented incidences of drug-associated anaphylaxis in Taiwan over a 9-year period. Methods: Cases of medication-associated anaphylaxis documented in the Taiwan National Health Insurance claims database during a span of 9 years (from January, 1997 to December, 2005) encompassing approximately 23 million person-years were reviewed. The database quantifies the drugs dispensed, clinical diagnoses, and patient demographics. Results: Overall, 92 reports of medication-associated anaphylaxis in 92 patients were identified with potential causative agents documented. In this group, nonsteroidal anti-inflammatory drugs (NSAIDs) and antibiotics were the main classes of medications most frequently implicated as the causative agent(s) in 89% of the cases. NSAIDs alone were implicated in 28% of cases, whereas antibiotics alone were implicated in another 28% of these cases. The use of multiple medications including either antibiotics or analgesics was documented in an additional one-third of the cases. A number of different NSAIDs including aspirin, diclofenac, ketoprofen, ketorolac, and meperidine were documented as the causative agents. Among the reported cases of antibiotics-induced anaphylaxis, cefazolin was the most frequently reported causative agent with 11 cases, followed by amoxicillin with four cases. Conclusion: Antibiotics and NSAIDs were the two main classes of medications most frequently implicated in the reports of anaphylaxis in the Taiwanese population. Although this may be related to the frequent use of these medications in the Taiwanese population, the observation here does advocate for reduced combination of NSAIDs and antibiotics, and more careful patient monitoring when they are combined.