When can blood thinners, such as warfarin (International Normalized Ratio (INR) monitor) or direct oral anticoagulants (DOACs) like apixaban (Eliquis) or rivaroxaban (Xarelto), be resumed after surgery?

Resuming Blood Thinners After Surgery

For patients on anticoagulation therapy, blood thinners should be resumed based on bleeding risk: DOACs should be restarted 24 hours after low bleeding risk procedures and 48-72 hours after high bleeding risk procedures, while warfarin should be resumed within 24 hours of surgery when adequate hemostasis is achieved. 1

Timing of Anticoagulant Resumption

Warfarin Resumption

• Timing: Resume within 24 hours after surgery (typically evening of surgery or next day) when adequate hemostasis is achieved 1
• Dosing: Use patient's usual maintenance dose rather than double dosing 1
• Rationale: Early resumption (within 24 hours) is associated with lower rates of thromboembolism (0.1%) compared to delayed resumption (2.4%) 1
• Important consideration: It takes 2-3 days for partial anticoagulant effect and 4-8 days for full effect 1

Direct Oral Anticoagulants (DOACs) Resumption

Low Bleeding Risk Surgery

• Timing: Resume 24 hours after surgery 1
• Dosing:
  • Dabigatran: 150 mg twice daily
  • Rivaroxaban: 20 mg once daily
  • Apixaban: 5 mg twice daily

High Bleeding Risk Surgery

• Timing: Resume 48-72 hours after surgery 1
• Dosing:
  • Dabigatran: 150 mg twice daily
  • Rivaroxaban: 20 mg once daily
  • Apixaban: 5 mg twice daily

Special Considerations for High Thromboembolism Risk Patients

• For patients at high risk of thromboembolism after high bleeding risk surgery:
  • Consider reduced initial dosing for 1-2 days:
    • Dabigatran: 110-150 mg once daily
    • Rivaroxaban: 10 mg once daily
    • Apixaban: 2.5 mg twice daily 1

Clinical Decision-Making Algorithm

1. Assess surgical bleeding risk:

   • Minimal risk (minor dental/skin procedures): May continue anticoagulation or stop only on day of procedure 2
   • Low-moderate risk (cholecystectomy, hernia repair): Resume DOACs 24 hours post-op 1, 2
   • High risk (major cancer surgery, joint replacement): Resume DOACs 48-72 hours post-op 1, 2

2. Assess patient's thromboembolism risk:

   • High risk: Consider reduced initial dosing for DOACs 1
   • Standard risk: Resume at regular dosing

3. Evaluate post-operative hemostasis:

   • Adequate hemostasis: Proceed with planned resumption
   • Inadequate hemostasis: Delay resumption until bleeding risk subsides 1

4. Special post-operative situations:

   • Major bowel surgery: Consider potential for limited oral medication absorption (typically resolves within 24-72 hours) 1
   • Anticipated additional interventions: Delay resumption 1
   • Unable to take oral medications: Delay resumption 1

Important Considerations and Pitfalls

• Rapid onset of action: DOACs reach peak levels 1-3 hours after ingestion, requiring caution when resuming (similar to treatment-dose LMWH) 1
• Avoid premature resumption: Starting full-dose anticoagulation too soon after surgery increases bleeding risk 1
• Drug interactions: In dabigatran-treated patients, acid-suppressive medications (common post-operatively) may affect absorption 1
• Apixaban-specific guidance: Per FDA label, apixaban should be restarted "as soon as adequate hemostasis has been established" 3
• Avoid bridging with heparin: For DOACs, bridging during the 24-48 hours after stopping is generally not required 3

By following these evidence-based recommendations, clinicians can optimize the balance between preventing thromboembolism and avoiding post-operative bleeding complications when resuming anticoagulation therapy after surgery.