The nurse аdministers PO аcetаminоphen with water tо a patient with a headache befоre a CT scan. The nurse then administers a contrast dye via IV for the CT scan. A few minutes later, the patient develops shortness of breath, wheezing, facial swelling, and a sudden drop in blood pressure. The nurse notes that the [BLANK-1] is most likely responsible for the [BLANK-2] reaction.