Yarema M, et al. - The incidence, risk factors, and treatment of anaphylactoid reactions to intravenous (IV) N-acetylcysteine (NAC) were determined in a large, national cohort of patients admitted to hospital for acetaminophen overdose. Researchers recognized an uncommon occurrence of anaphylactoid reactions to the 21-h IV NAC protocol. These reactions primarily involved cutaneous symptoms. The protective effects of higher APAP concentrations were valuable for understanding the pathophysiology, however, none of the associations identified were strong enough to substantially alter the threshold for NAC initiation.