Protamine Sulfate

A solution of protamine sulfate is injected slowly intravenously by jet or drip. The rate of administration should not exceed 5 mg per minute (for example, 50 mg of the drug should be administered within 10 minutes), since a faster administration may cause an anaphylactoid reaction. The dose of the drug depends on the route of administration of heparin. The calculated dose is dissolved in 300-500 ml of 0.9% sodium chloride solution. Do not administer more than 150 mg protamine sulfate in 1 hour.

1. With bolus injections of heparin, the dose of protamine sulfate decreases depending on the time elapsed from the administration of heparin, since the latter is continuously removed from the body.

Time elapsed after heparin injection Dose of protamine sulfate per 100 IU of heparin

15-30 minutes 1-1.5 mg

30-60 minutes 0.5-0.75 mg

Over 2 hours 0.25-0.375 mg

2. If heparin was injected intravenously, it is necessary to stop its infusion and inject 25-30 mg of protamine sulfate.

3. For subcutaneous injections of heparin, the dose of protamine sulfate is 1 - 1.5 mg for every 100 IU of heparin. The first 25-50 mg of protamine sulfate should be administered intravenously slowly, and the remaining dose should be administered intravenously over 8-16 hours. Perhaps fractional introduction of protamine sulfate, which requires control of activated partial thromboplastin time (APTT). For example, if 20,000 IU of heparin is injected subcutaneously, after 2 hours, heparin is resorbed from complexes with protamine at 3333 IU of heparin, therefore the next dose of protamine sulfate is 33 mg.

4. In the case of using extracorporeal circulation during surgery, the dose of protamine sulfate is 1.5 mg for every 100 IU of heparin. When determining the dose of protamine, it is necessary to take into account the route of administration of heparin.