A solution of protamine sulfate is injected slowly intravenously in a stream or drip.The rate of administration should not exceed 5 mg per minute (eg, 50 mg of the drug administered within 10 minutes), since a more rapid administration may cause an anaphylactoid reaction. The dose of the drug depends on the method 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 of protamine sulfate for 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 past after injections of heparin: | The 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 introduce 25-30 mg of protamine sulfate.
3. With subcutaneous injections of heparin, the dose of protamine sulfate is 1-1,5 mg for every 100 ME heparin. The first 25-50 mg of protamine sulphate should be administered intravenously slowly, and the remaining dose - intravenously drip during 8-16 hours. Probably fractional administration of protamine sulfate, which requires control of activated partial thromboplastin time (APTT). For example, if administered subcutaneously 20000 ME heparin, after 2 hours resorption of heparin from complexes with protamine to 3333 ME heparin, in this regard, 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 per 100 ME heparin. When determining the dose of protamine, it is necessary to take into account the route of administration of heparin.