Hypersensitivity reactions are rare in patients with no prior exposure to aprotinin.
Hypersensitivity reactions can range from skin eruptions, itching, dyspnea , nausea and tachycardia to fatal anaphylactic shock with circulatory failure. If a hypersensitivity reaction occurs during injection or infusion of Trasylol, administration should be stopped immediately and emergency treatment should be initiated. Even when a second exposure to aprotinin has been tolerated without symptoms, a subsequent administration may result in severe hypersensitivity anaphylactic reactions. The relationship of these 2 deaths to Trasylol is unclear. Other smaller studies have shown that in case of re-exposure, the incidence of hypersensitivity anaphylactic reactions may reach the five percent level.