Bridging from LMWH to Apixaban is Not Recommended
No bridging or overlap period is required when transitioning from LMWH to apixaban, as apixaban has a rapid onset of action making traditional bridging unnecessary. 1
Rationale for Not Bridging
- Unlike warfarin transitions which require 5-7 days of overlap therapy, direct oral anticoagulants (DOACs) like apixaban reach therapeutic levels quickly and do not require bridging 1
- Overlapping LMWH with apixaban significantly increases bleeding risk without providing additional thrombotic protection 1
- Bridging patients on anticoagulants with LMWH is primarily indicated for transitioning to/from vitamin K antagonists (like warfarin), not for DOACs like apixaban 2
Proper Transition Protocol
- For patients on twice-daily LMWH: Start apixaban at the time the next LMWH dose would have been due 1
- For patients on once-daily LMWH: Start apixaban 12 hours after the last LMWH dose 1
- For patients on prophylactic-dose LMWH: Start apixaban at the time the next prophylactic LMWH dose would have been scheduled 1
Special Considerations
- Renal function should be monitored closely, as both LMWH and apixaban are affected by renal impairment 1
- Apixaban requires dose adjustment with severe renal impairment (CrCl <30 mL/min) 3
- In patients with severe renal failure, apixaban has shown a significantly lower rate of major bleeding (RR, 0.72; 95% CI, 0.62-0.84) and minor bleeding events (RR, 0.42; 95% CI, 0.21-0.86) compared to warfarin 3
Common Pitfalls to Avoid
- Unnecessary bridging: DOACs like apixaban do not require bridging with LMWH due to their rapid onset of action 1
- Medication overlap: Overlapping LMWH with apixaban significantly increases bleeding risk without additional thrombotic protection 1
- Incorrect timing: Starting apixaban too soon after LMWH can lead to excessive anticoagulation and bleeding risk 1
Specific Clinical Scenarios
- For patients undergoing surgery: If venous thromboprophylaxis is indicated before full anticoagulation can be safely restarted, consider using prophylactic doses of LMWH starting at least 6 hours after surgery, then transition to apixaban following the standard protocol 4
- For patients with cancer-associated VTE: Both apixaban and LMWH are recommended options for long-term anticoagulation (at least 6 months) 2
- For patients with mechanical heart valves: A standardized LMWH bridging regimen has been shown to be effective and relatively safe, but this applies to bridging from warfarin, not to transitioning to apixaban 5
In conclusion, when transitioning from LMWH to apixaban, simply start apixaban when the next dose of LMWH would have been due, with no overlap period required.