Protamine

Protamine is an FDA-approved drug for use in neutralizing the effect of unfractionated heparin.[1][2] It is most commonly used to neutralize heparin-induced anticoagulation after separation from cardiopulmonary bypass. When appropriately dosed, this neutralization reduces the risk of postoperative bleeding.[3] Protamine is also utilized to reverse the anticoagulation effects of unfractionated heparin in the setting of dialysis, invasive vascular procedures, and acute ischemic strokes.[4] Finally, clinicians can use protamine for a partial reversal of low molecular weight heparins including enoxaparin, dalteparin, and tinzaparin, but the degree of reversal is unclear, and this use has not been FDA-approved.[2] Currently, protamine is produced using recombinant technology, but it was originally isolated from salmon fish sperm.[3] When first introduced, protamine was used to prolong the action of insulin preparations; adding it to the preparation prolonged the duration of action of the insulin and delayed insulin absorption.