When to administer Enoxaparin (Low Molecular Weight Heparin) intravenously?

From the Guidelines

Enoxaparin should be administered intravenously in specific clinical scenarios, such as during percutaneous coronary intervention (PCI), with a single bolus dose of 0.5-0.75 mg/kg, as recommended by the most recent and highest quality study 1.

Key Considerations

• The standard route of administration for enoxaparin is subcutaneous injection, usually in the abdomen, with dosing based on patient weight and indication, as outlined in the 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes 1.
• Intravenous administration of enoxaparin is limited to the catheterization laboratory setting under direct medical supervision, where immediate anticoagulation effect is necessary to prevent thrombotic complications during procedures like angioplasty.
• The rationale for IV administration in these limited circumstances is to achieve rapid anticoagulant effect, as subcutaneous administration has a delayed onset of action (approximately 20-60 minutes).

Clinical Scenarios for IV Administration

• For patients who have not received previous antithrombin therapy, enoxaparin may be administered intravenously (0.5–0.75 mg/kg IV bolus) at the time of PCI, as recommended by the 2016 update on antithrombotic therapy in patients with atrial fibrillation undergoing percutaneous coronary intervention 1.
• For ACS patients treated with upstream subcutaneous enoxaparin, an additional dose of 0.3 mg/kg IV should be administered at the time of PCI to those who have received <2 therapeutic subcutaneous doses or received the last subcutaneous enoxaparin dose 8 to 12 hours before PCI.

Important Notes

• The use of intraprocedural parental antithrombotic agents should be tailored to the individual patient's risk profile, with consideration of the potential benefits and risks of each agent, as discussed in the 2016 update on antithrombotic therapy in patients with atrial fibrillation undergoing percutaneous coronary intervention 1.
• The choice of intraprocedural anticoagulation should be guided by the patient's clinical presentation, medical history, and the specific procedure being performed, with the goal of minimizing the risk of thrombotic complications and bleeding events.

From the FDA Drug Label

For patients younger than 75 years of age, enoxaparin sodium was given as a single 30 mg intravenous bolus plus a 1 mg/kg subcutaneous dose followed by a subcutaneous injection of 1 mg/kg every 12 hours For patients at least 75 years of age, the intravenous bolus was not given and the subcutaneous dose was reduced to 0. 75 mg/kg every 12 hours. For patients with severe renal insufficiency (estimated creatinine clearance of less than 30 mL per minute), the dose was to be modified to 1 mg/kg every 24 hours. When percutaneous coronary intervention was performed during study medication period, patients received antithrombotic support with blinded study drug. For patients on enoxaparin sodium, the PCI was to be performed on enoxaparin sodium (no switch) using the regimen established in previous studies, i. e. no additional dosing, if the last subcutaneous administration was less than 8 hours before balloon inflation, intravenous bolus of 0. 3 mg/kg enoxaparin sodium if the last subcutaneous administration was more than 8 hours before balloon inflation.

The Enoxaparin Intravenous should be given:

• As a single 30 mg intravenous bolus in patients younger than 75 years of age
• With no intravenous bolus in patients at least 75 years of age
• As an intravenous bolus of 0.3 mg/kg when the last subcutaneous administration was more than 8 hours before balloon inflation during percutaneous coronary intervention 2

From the Research

Enoxaparin Administration

• Enoxaparin is typically administered subcutaneously, but there is limited information on its intravenous administration 3, 4, 5, 6, 7.
• The studies provided do not specify when to give Enoxaparin intravenously, but they do discuss its use in various clinical settings, such as acute coronary syndrome and percutaneous coronary intervention 3, 5, 7.

Clinical Settings

• In patients with acute coronary syndrome, Enoxaparin is often used as an anticoagulant, but the studies do not provide guidance on intravenous administration 3, 5.
• In percutaneous coronary intervention, low-molecular-weight heparin, including Enoxaparin, has been compared to unfractionated heparin, but the studies focus on subcutaneous or intravenous administration of low-molecular-weight heparin in general, rather than Enoxaparin specifically 7.

Renal Insufficiency

• Patients with renal insufficiency may require dose reduction or careful monitoring when using Enoxaparin, but the studies do not provide specific guidance on intravenous administration in this population 4.
• The use of Enoxaparin in patients with severe renal insufficiency requires careful consideration and monitoring, but the optimal route of administration is not specified 4.

Pharmacology and Clinical Applications

• Enoxaparin has been shown to be effective in preventing and treating thromboembolic disorders, but the studies do not provide detailed information on its intravenous administration 5, 6.
• The pharmacokinetic and pharmacodynamic properties of Enoxaparin are well-established, but the studies do not discuss its intravenous administration in detail 5, 6.