For IV heparin:
- Protamine sulfate dosing is 1 mg per 100 units of heparin, if heparin was given in the previous 2-3 hours.
- Protamine sulfate is given slower than 5 mg/minute to minimize the risk of adverse reactions.
- Maximum dose of protamine sulfate is 50 mg.
For SC heparin:
- When heparin has been given subcutaneously (and therefore is cleared with a longer half-life) prolonged or repeated administration of protamine sulfate may be required.