What are the next steps for treating inpatient pulmonary embolism with Lovenox (enoxaparin) 90mg once daily?

Management of Inpatient Pulmonary Embolism After Initial Enoxaparin Dose

For inpatient pulmonary embolism initially treated with enoxaparin 90mg once, the next step should be to adjust to the appropriate therapeutic dosing regimen of either enoxaparin 1mg/kg twice daily or 1.5mg/kg once daily, followed by transition to a direct oral anticoagulant (DOAC) such as rivaroxaban or apixaban for continued treatment.

Immediate Next Steps

1. Verify appropriate enoxaparin dosing:

   • The initial 90mg once dose is inadequate for therapeutic anticoagulation
   • Adjust to weight-based therapeutic dosing:
     • Enoxaparin 1mg/kg subcutaneously every 12 hours, OR
     • Enoxaparin 1.5mg/kg subcutaneously once daily 1

2. Assess patient for risk stratification:

   • Evaluate hemodynamic stability
   • Check for right ventricular dysfunction on echocardiography
   • Consider cardiac biomarkers (troponin, BNP)
   • Determine if massive, submassive, or low-risk PE

Transition to Oral Anticoagulation

Preferred Option: DOAC Therapy

• Rivaroxaban:

  • 15mg twice daily for 21 days, followed by 20mg once daily 1, 2
  • Can be started 0-2 hours before next scheduled enoxaparin dose 2
  • No need for LMWH bridging

• Apixaban (alternative):

  • 10mg twice daily for 7 days, followed by 5mg twice daily 1, 2
  • Associated with lower risk of major bleeding 2

• Other DOAC options:

  • Edoxaban: Requires 5+ days of parenteral anticoagulation first, then 60mg once daily (or 30mg if CrCl 30-50mL/min or weight <60kg) 2
  • Dabigatran: Requires 5+ days of parenteral anticoagulation first, then 150mg twice daily 2

Alternative: Vitamin K Antagonist (Warfarin)

• Continue enoxaparin while initiating warfarin
• Overlap for minimum 5 days and until INR is 2-3 for two consecutive days 1
• Target INR 2-3 for maintenance therapy

Duration of Anticoagulation

• First PE with major transient/reversible risk factor: 3 months 2
• Unprovoked PE or persistent risk factors: Extended anticoagulation (>3 months) 2
• Recurrent VTE: Indefinite anticoagulation 2

Special Considerations

Cancer Patients

• LMWH monotherapy (dalteparin 200 U/kg once daily for 1 month, then 150 U/kg once daily) is preferred for at least 6 months 1
• Enoxaparin 1mg/kg twice daily may be more effective than 1.5mg/kg once daily in cancer patients 3

Monitoring Requirements

• Monitor platelet count during LMWH therapy due to risk of heparin-induced thrombocytopenia 1
• For patients with severe renal impairment or during pregnancy, consider monitoring anti-Xa levels 1
• Assess renal and hepatic function before initiating DOACs and periodically during treatment 2

Advantages of DOACs over Traditional Therapy

• Fixed dosing without need for routine monitoring
• Fewer food and drug interactions
• Lower risk of intracranial bleeding
• No need for bridging during temporary interruptions
• Potential for shorter hospital stays 1

Contraindications to DOACs

• Severe renal impairment (CrCl <30 mL/min)
• Severe hepatic impairment
• Antiphospholipid antibody syndrome
• Pregnancy or lactation
• Prosthetic heart valves 2

Common Pitfalls to Avoid

• Underdosing initial therapy: The initial 90mg dose of enoxaparin is inadequate; weight-based dosing is essential for therapeutic effect
• Delaying oral anticoagulation: Begin planning for transition to oral therapy early in hospitalization
• Inappropriate DOAC selection: Consider patient-specific factors (renal function, drug interactions, compliance concerns)
• Inadequate overlap when transitioning to warfarin: Ensure minimum 5 days of overlap and INR 2-3 for two consecutive days before stopping parenteral therapy
• Failing to schedule follow-up: Plan for reassessment at 3-6 months to evaluate for chronic complications 2