ABSTRACT
N-acetylcysteine [NAC] is the choice treatment for acetaminophen overdose. The main side effect of intravenous NAC therapy is anaphylaxis or anaphylactoid reactions. We investigated the prevalence of anaphylactoid or anaphylaxis reactions to IV-NAC therapy in acetaminophen poisoned patients with atopic disease. A case series antrograde and descriptive'analytic study was done on acetaminophen poisoned patients who treated with IV-NAC from September 2003 to September 2004 in Isfahan, Iran. Of 173 infused IV-NAC patients, 77 patients [44.5%] developed an anaphylactoid reaction. Its side effects was nausea and vomiting [n=49, 63.15%], flashing [n=23, 30.26%], bronchospasm [n=20, 26.31%], vertigo [n=18, 23.68%], skin rash [n=25, 32.36%] and hypotension [n=12, 15.75%]. Also, 71 patients [41%] had history of atopic disease. Atopic diseases were asthma [n=12, 6.9%], atopic dermatitis [n=7, 4%], allergic rhinitis [n=5, 2.8%] and allergic conjunctivitis [n=1, 0.5%]. Among 71 atopic patients, 59 patients [83.13%] developed side effects to NAC. There was a relation between previous history of atopic disease and anaphylactoid reaction to NAC. We report substantially higher incidence of anaphylactoid reactions to IV-NAC than previous studies. Different atopic diseases must be considered as a risk factor in the development of side effects to IV-NAC-therapy