Atopic Diseases: Risk Factor in developing Adverse Reaction to Intravenous N-Acetyl cysteine

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.