Progressive granulocytopenia (neutrophil count <1000/ml) developed in a newborn during treatment with propafenone (200 mg/m2) for recurrent paroxysmal supraventricular tachycardia. The total white blood cell count, however, remained within normal limits. The neutrophil count increased gradually after propafenone had been stopped. The time course of treatment and the development of granulocytopenia make it very likely, but not certain, that propafenone was the responsible agent. Pediatricians, and especially pediatric cardiologists, should be aware of this rare adverse effect when they consider treatment with propafenone in children with cardiac arrhythmias. Analysis of the white cell blood count, including a differential count, is recommended in all children in order to assess the true incidence of this adverse effect.

This case describes a 29-year-old woman who presented with an acute severe anaphylactic reaction to penicillin. In addition to other medications administered in the emergency department, she received 0.1 mg intravenously of 1:10 000 epinephrine, after which she immediately developed severe chest pain. Her ECG showed ST elevations consistent with an anterior myocardial infarction, and her serum troponin level was elevated. A CT angiogram showed no signs of coronary artery disease or abnormal anatomy. This case is an example of vasospasm-induced myocardial injury and illustrates a potential danger of intravenous epinephrine use. The authors were able to identify only 2 other case reports where therapeutic doses of epinephrine have been reported to cause this phenomenon.