An anaphylactic reaction to protamine sulfate.

Presented is a case in which protamine sulfate administration caused an immediate allergic-like reaction. The patient, a 50-year-old woman, had received protamine previously to reverse the anticoagulant effect of heparin after open heart surgery. In a similar operation 7 years later, protamine was used again for the same reason. Immediately following intravenous infusion of 3 mg/kg protamine sulfate, a sudden drop of the mean arterial blood pressure to 40 mm Hg occurred, and the heart rate increased from 100 to 130 beats/min. Severe angioneurotic edema of the face and trunk also developed. The reaction was successfully treated with vasopressors, steroids, and volume expansion. Subsequent skin testing revealed a positive reaction to protamine sulfate.