Key points

  • We recommend to consult your poison centre with the use of this antidote.
  • Onset of action is about 5 minutes; duration of action is about 2 hours.
  • Administered alone, protamine exerts an anticoagulant effect. However, when administered in the presence of heparin (a strongly acidic substance) a stable salt is formed, resulting in loss of anticoagulant activity for both agents.
  • A larger than necessary (> 6 mg/kg) dose of protamine can therefore have an anticoagulant effect and inhibit platelet formation. It is generally better to administer a lower dose than a higher one.

Last updated : 2023-08-31