PROTAMINE injectable

Prescription under medical supervision

Therapeutic action

– Neutralisation of the anticoagulant action of unfractionated heparin
– Partial neutralisation of the anticoagulant action of low molecular weight heparin


– Haemorrhagic syndromes resulting from accidental heparin overdosage

Forms and strengths, route of administration

– 50 mg protamine sulfate in 5 ml ampoule (10 mg/ml) for slow IV injection
Concentration may be expressed in antiheparin units (AHU): 1000 AHU = 10 mg.


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 for any one dose.

– Nadroparin overdosage
1 mg of protamine sulfate (100 AHU) neutralises 100 units of nadroparin. The dose of protamine to be given is equal to that of the nadroparin injected.


– 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


– In the case of nadroparin overdose, it is recommended to administer 1 or 2 units of fresh whole blood at the same time to counteract its activity against Factor Xa.
– Anticoagulant effect 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) -