Protamine is an anticoagulant reversal agent that helps to stop bleeding caused by heparin. Protamine is typically given in a hospital setting as an intravenous (IV) injection over 10 minutes. And it begins to work within 5 minutes. Side effects include low blood pressure and slow heart rate, so your provider will keep an eye on these to make sure they don't drop too low.
To treat bleeding caused by heparin
Protamine is an anticoagulant reversal agent. It works by attaching to heparin and preventing it from making your blood thinner. This way, it stops any bleeding that might be happening.
Source:Â DailyMed
Works quickly to reverse the effects of heparin
Given as an IV injection over 10 minutes
Needs to be given in a healthcare setting
Can suddenly lower blood pressure and heart rate
Your provider will order blood tests (e.g., complete blood count) and examine you for signs and symptoms of bleeding after receiving protamine to see how well you respond to the medication.
Make sure to let your provider know if you are taking a blood thinner at home. They'll decide if and when you should restart it after receiving protamine.
Protamine can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Risk factors: Rapid administration of protamine | High dose of protamine | Repeated doses of protamine | Using other medications that also contain protamine
Although rare, protamine can cause severe heart problems, including low blood pressure, slow heart rate, sudden collapse, and fluid overload in the lungs. Your provider will monitor your vitals closely before, during, and after you receive protamine and provide treatment if needed.
Serious allergic reactions to protamine are possible, including life-threatening reactions like anaphylaxis (e.g., closing of the throat). Your provider will monitor you for symptoms like dizziness, nausea, a choking sensation, difficulty breathing, swelling around your eyes, or swelling of the lips or tongue while you're receiving protamine.
Your provider will help determine your dose. The typical dose depends on the amount of heparin you receive. Each 1 mg of protamine is given for about every 100 units of heparin. The maximum dose is 50 mg.
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Applefield, D., et al. (2023). Protamine. StatPearls.
Dhakal, P., et al. (2016). Reversal of anticoagulation and management of bleeding in patients on anticoagulants. Clinical and Applied Thrombosis/Hemostasis.
Frenesius Kabi USA, LLC. (2023). Protamine sulfate injection, solution [package insert]. DailyMed.
Hafner, C., et al. (2012). 390 Protamine allergy. The World Allergy Organization Journal.
Pearson, P. J. (1992). Protamine releases endothelium-derived relaxing factor from systemic arteries. A possible mechanism of hypotension during heparin neutralization. Circulation.
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