The administration of protamine sulfate is currently widely used method of reversing heparin anticoagulation after the cardiac surgery. Protamine, a basic polypeptide derived from salmon sperm, reverses heparin, an acidic glycosaminoglycan derived from bovine or porcine tissues by nonspecific acid-base interactions to form heparin-protamine complexes. Anaphylactic reactions to protamine that they have been reported in patients with fish allergy such as salmon sperm and in those previously exposed to protamine, principally diabetics who have received protamine zinc insulin or vasectomised men via antibodies raised to protamine contained in sperm released into the blood stream. The life-threatening reactions to protamine appear to represent anaphylaxis due to prior sensitization. However, protamine administration has occasionally been associated with clinically significant side effects, including systemic decreased arterial pressure, bradycardia, cardiovascular collapse, and pulmonary hypertension. Incidence of protamine allergy is 0.28%-2.6%.