Severe anaphylactic reaction after primary exposure to aprotinin.

Aprotinin is widely used to prevent bleeding and reduce blood transfusions after open heart surgical procedures. Because it is a foreign protein, aprotinin has allergenic potential. We report a case of near-fatal anaphylactic reaction to primary aprotinin exposure in a child successfully treated using cardiopulmonary bypass support. The possibility of an allergic reaction must be considered whenever this drug is used.