Urushidani S, et al. - Researchers here report the case of a 60-year-old man who was previously healthy but presented to the emergency department with anaphylactic shock. Fluid resuscitation with Ringer's lactate solution was started, and 0.3 mg epinephrine was injected intramuscularly. The patient was given d-chlorpheniramine maleate 5 mg, famotidine 20 mg, and methylprednisolone 80 mg intravenously. Thereafter, symptoms settled within 10 min. The patient experienced sudden chest discomfort 30 minutes after the epinephrine injection, and to treat this, he was given 0.3 mg of sublingual nitroglycerin, after which his chest pain resolved quickly and his ECG normalized. Slight rise in his high-sensitivity troponin I was detected the next day and myocardial ischemia induced by coronary artery spasm was suspected. The symptoms of biphasic reaction of anaphylaxis were inconsistent, and the use of epinephrine for myocardial ischemia after anaphylaxis may worsen the condition. Physicians are advised not to be reluctant to use epinephrine for patients having life-threatening conditions because of suspected anaphylaxis. Vigilance on the part of physicians should be practiced regarding the risk of myocardial ischemia following the treatment of anaphylaxis, particularly after epinephrine use.