PREVALENCE OF CROSS-SENSITIVITY WITH ACETAMINOPHEN IN ASPIRIN-SENSITIVE ASTHMATIC SUBJECTS

Objective: Cross-sensitivity between aspirin and acetaminophen in aspi rin-sensitive asthmatic patients has been reported with frequencies ra nging from 0% to 29%. The relationship is dose-dependent for acetamino phen challenges, ranging between 300 and 1000 mg. Methods: To determin e the prevalence of cross-sensitivity to high-close acetaminophen, we performed single-blind acetaminophen oral challenges with 1000 mg and 1500 mg in 50 aspirin-sensitive asthmatic patients and in 20 non-aspir in-sensitive asthmatic control subjects. Results: Overall, 17 of 50 (3 4%) of aspirin-sensitive asthmatic patients reacted to acetaminophen i n doses of 1000 to 1500 mg (95% confidence interval: 20% to 49%). By c ontrast, none of the 20 non-aspirin-sensitive asthmatic patients react ed to acetaminophen (95% confidence interval: 0% to 14%). This differe nce was highly significant (p = 0.0013), supporting the hypothesis tha t cross-sensitivity between aspirin. and acetaminophen is unique in as pirin-sensitive asthmatic patients. Conclusion: Although high-dose (>1 000 mg) acetaminophen cross-reactions with aspirin were significant wi th respect to frequency (34%), such reactions included easily reversed bronchospasm in only 22%, and were generally mild. We recommend that high doses of acetaminophen (1000 mg or greater) should be avoided in aspirin-sensitive asthmatic patients.