ATOPY AND INTOLERANCE OF ANTIMICROBIAL DRUGS INCREASE THE RISK OF REACTIONS TO ACETAMINOPHEN AND NIMESULIDE IN PATIENTS ALLERGIC TO NONSTEROIDAL ANTIINFLAMMATORY DRUGS

This study evaluated the risk factors for developing allergic reaction s to alternative drugs such as acetaminophen and nimesulide in 367 pat ients intolerant of nonsteroidal anti-inflammatory drugs (NSAID) compa red to 243 healthy controls. All subjects were given test doses (TD) o f acetaminophen and nimesulide, and age, sex, atopy, and history of re actions also to unrelated drugs were compared In those who reacted and those who were tolerant of the challenge. TD was positive in 49 of 36 7 (14%) NSAID-allergic patients and in one (0.4%) of the controls (P<0 .001). No difference was found in age and sex between the TD-positive and TD-negative subjects, although a significantly larger number of fe males were NSAID allergic (P<0.01). Of the 367 patients, 208 had a his tory of reactions only to NSAID, and 148 to NSAID and antimicrobial dr ugs (AMD). TD vith acetaminophen or nimesulide was positive in 6% of p atients intolerant only of NSAID and in 24% of those intolerant of bot h NSAID and AMD, with an odds ratio of 4.82. Atopy was more frequent a mong patients (36%) than controls (23%) (P=0.004), among TD-positive ( 51%) than TD-negative patients (33.5%) (P<0.02), and among patients in tolerant of NSAID and AMD (48%) than those intolerant only of NSAID (P =0.006). The odds ratios were, respectively, 1.87, 2.57, and 3.16. Thi s study provides evidence that atopy and history of allergic reactions to AMD increase the likelihood of intolerance of usually well-tolerat ed alternative drugs such as acetaminophen and nimesulide in subjects allergic to NSAID.