Therapeutic action
- Neutralisation of the anticoagulant action of unfractionated heparin
- Partial neutralisation of the anticoagulant action of low molecular weight heparin
Indications
- Haemorrhagic syndromes resulting from accidental heparin overdosage
Forms and strengths, route of administration
- 50 mg protamine sulfatein 5 ml ampoule (10 mg/ml) for slow IV injection Concentration may be expressed in antiheparin units (AHU): 1000 AHU = 10 mg.
Dosage
Depends on the amount of heparin to be neutralised.
Heparin overdosage
- If administered between 0 and 30 minutes after the heparin injection, 1 mg of protamine sulfate (100 AHU) neutralises 100 units of heparin.
- If more than 30 minutes have elapsed since the heparin injection, the dose of protamine to be given should be one half the dose of heparin injected.
- Do not administer more than 50 mg per dose
Enoxaparin overdosage
| Time since last enoxaparin dose | Protamine dose |
| < 8 hours | 1 mg per 1 mg enoxaparin |
| > 8 hours and < 12 hours | 0.5 mg per 1 mg enoxaparin |
| > 12 hours | May not be required |
- Do not administer more than 50 mg per dose.
Duration
- According to clinical response.Monitor coagulation parameters.
Contra-indications, adverse effects, precautions
- May cause: hypotension, bradycardia and dyspnoea; allergic reactions, notably in diabetics treated by protamine-insulin.
- If excessive doses are used, haemorrhage may persist or reappear, as protamine sulfate itself has some anticoagulant activity.
- Administer by very slow IV (over 10 minutes)in order to reduce risks of hypotension and bradycardia.
- Pregnancy: no contra-indication
- Breast-feeding: no contra-indication
Remarks
- Anticoagulant effectn of protamine may vary according to the origin of the heparin: follow manufacturer's recommendations.
- Protamine sulfate may be used to neutralize the effect of heparin before surgery.
Storage
– To be kept refrigerated (2 °C to 8 °C)