From the Guidelines
The antidote for Lovenox (enoxaparin) is protamine sulfate, which should be administered intravenously to neutralize its anticoagulant effects in cases of significant bleeding. When a patient experiences significant bleeding while on Lovenox, protamine sulfate can be used to partially reverse its effects. The dosing of protamine sulfate depends on the timing of the last Lovenox dose:
- 1 mg of protamine per 1 mg of Lovenox if given within 8 hours,
- or 0.5 mg of protamine per 1 mg of Lovenox if given within 8–12 hours 1. Protamine can only partially neutralize Lovenox, which is less effective than its complete reversal of unfractionated heparin. This partial neutralization occurs because protamine primarily binds to the longer chains in Lovenox's molecular structure.
- Healthcare providers should monitor patients closely after administration for signs of bleeding resolution and potential adverse reactions to protamine,
- which can include hypotension, bradycardia, and allergic reactions 1. Patients with fish allergies or previous protamine exposure may have increased risk of allergic reactions.
- It is essential to note that the clinical significance of incomplete anti-Xa neutralization of LMWH by protamine sulfate is unclear,
- and the use of protamine sulfate is based on a strong recommendation with moderate quality evidence 1. In cases where life-threatening bleeding persists, or the patient has renal insufficiency, redosing protamine may be considered 1.
From the FDA Drug Label
Injected enoxaparin sodium may be largely neutralized by the slow intravenous injection of protamine sulfate (1% solution) The dose of protamine sulfate should be equal to the dose of enoxaparin sodium injected: 1 mg protamine sulfate should be administered to neutralize 1 mg enoxaparin sodium, if enoxaparin sodium was administered in the previous 8 hours.
The antidote for Lovenox (enoxaparin) is protamine sulfate.
- The dose of protamine sulfate should be equal to the dose of enoxaparin sodium injected.
- 1 mg protamine sulfate should be administered to neutralize 1 mg enoxaparin sodium, if enoxaparin sodium was administered in the previous 8 hours 2.
- Note that the anti-Factor Xa activity is never completely neutralized (maximum about 60%) 2.
From the Research
Lovenox Antidote
- Lovenox, also known as enoxaparin, is a low-molecular-weight heparin (LMWH) used as an anticoagulant to prevent and treat blood clots.
- The antidote for Lovenox is protamine sulfate, which can partially reverse its anticoagulant effects 3, 4, 5, 6.
- Protamine sulfate is more effective in neutralizing the bleeding side-effects of enoxaparin than its anti-factor Xa activity 3, 5.
- The dosage of protamine sulfate for reversing enoxaparin-induced bleeding may depend on the time from last administration and dose of enoxaparin, as well as the patient's renal function and anti-Xa assay results 4, 7.
- While protamine sulfate can reduce bleeding induced by enoxaparin, it may not completely reverse its anticoagulant activity 3, 7, 5, 6.
- Other treatments, such as transfusion of blood products and use of specific antidotes, may be necessary in cases of major bleeding related to enoxaparin 6.