Reversing Low Molecular Weight Heparin (LMWH)

Protamine Administration

• Reversing unfractionated heparin with protamine is fairly straightforward and is an effective treatment.

• With enoxaparin and other LMWH, protamine is less effective at reversing anticoagulation. Using protamine, the maximum reversal of the whole effect of exoxaparin is approximately 60%. This is because protamine neutralises the anti-IIa (minor) effect of enoxaparin, but the anti-Xa (major) effect is not completely neutralised.

No Active Bleeding or Minor Bleeding	LMWH has a longer half life than unfractionated heparin (UFH), but if there is only minor bleeding, stopping the subcutaneous LMWH is sufficient.
Major Bleeding	In life-threatening bleeding, use protamine sulphate at a dose of 1mg per mg enoxaparin administered (eg 70mg enoxaparin, give 70mg protamine) A second dose of 0.5mg protamine / 1mg enoxaparin may be administered if haemorrhaging continues.
	Time Elapsed Since Last Enoxaparin Dose
	<8h: 1mg protamine / 1mg enoxaparin
	>8h and <12h: 0.5mg protamine / 1mg enoxaparin
	>12h: May not be required (due to half-life of Clexane)

· Protamine to be administered at a rate not exceeding 5mg / minute

• Adverse effects of protamine include a fall in blood pressure, bradycardia, dyspnoea and flushing. Particular care should be taken to avoid overdosage with protamine sulphate

• The time elapsed since the enoxaparin dose to be neutralised is important in the calculation of the protamine dose required. The table above should serve as a guide.

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