Fraxiparine Dosing for Post-PCI Patient Before Colonoscopy
For a ~100 kg patient who had PCI and is on aspirin, administer nadroparin (Fraxiparine) 5,700 IU anti-Xa subcutaneously once daily starting 12 hours after the last aspirin dose and continuing until 12 hours before the colonoscopy.
Weight-Based Dosing for Nadroparin
The standard prophylactic dosing of nadroparin is weight-adjusted according to established protocols: 1
- 50-69 kg: 3,800 IU anti-Xa once daily
- 70-89 kg: 5,700 IU anti-Xa once daily
- 90-100 kg: 5,700 IU anti-Xa once daily
- >100 kg: 7,600 IU anti-Xa once daily 1
For your patient at approximately 100 kg (or slightly more), the appropriate dose is 5,700 IU anti-Xa subcutaneously once daily. If the patient weighs definitively over 100 kg, increase to 7,600 IU anti-Xa once daily. 1
Timing Relative to Colonoscopy
Aspirin should be discontinued 5 days before the colonoscopy to minimize bleeding risk during the procedure. 1 During this aspirin-free period, nadroparin provides thromboprophylaxis to bridge the patient through the periprocedural period given the recent PCI. 1
Administer the last dose of nadroparin at least 12 hours before the colonoscopy. 2 This timing allows adequate clearance of anticoagulant effect while maintaining thromboembolic protection until shortly before the procedure. 1
Post-Colonoscopy Resumption
Resume nadroparin 12 hours after the colonoscopy, provided adequate hemostasis has been achieved. 1 Restart aspirin 75-100 mg daily once the procedural bleeding risk has resolved, typically 24-48 hours post-colonoscopy depending on whether biopsies or polypectomies were performed. 1, 3
Critical Safety Considerations
Do not administer unfractionated heparin (UFH) to this patient while on nadroparin—this combination significantly increases major bleeding risk without improving efficacy. 1 The FRAX.I.S. trial demonstrated that nadroparin 86 anti-Xa IU/kg twice daily (therapeutic dosing) had similar efficacy to UFH in unstable angina/NSTEMI patients, but your patient requires only prophylactic once-daily dosing given the elective colonoscopy context. 1, 4
Check the patient's renal function before dosing. While nadroparin dosing adjustments for renal impairment are less stringent than for enoxaparin, patients with creatinine clearance <30 mL/min require careful monitoring for drug accumulation. 1, 5
Verify the INR is not elevated from any concurrent vitamin K antagonist therapy. If INR >1.5, postpone the colonoscopy until anticoagulation is better controlled. 1, 2
Rationale for This Approach
The 2009 European Society of Cardiology perioperative guidelines specifically address bridging anticoagulation for patients at high thromboembolic risk undergoing non-cardiac surgery. 1 Post-PCI patients on aspirin have moderate-to-high thromboembolic risk, particularly within the first year after stent placement. 1
Prophylactic-dose nadroparin (not therapeutic-dose) is appropriate for colonoscopy bridging because the procedure itself is not a high-risk thrombotic event—the goal is simply to maintain baseline protection during the brief aspirin interruption. 1 Therapeutic anticoagulation would unnecessarily increase bleeding risk during a procedure where mucosal injury is expected. 1
The FRAX.I.S. trial used therapeutic nadroparin dosing (86 anti-Xa IU/kg twice daily) for acute coronary syndrome treatment, which is not applicable to your stable post-PCI patient. 1, 4 For periprocedural bridging in stable patients, once-daily prophylactic dosing based on weight is the standard of care. 1
Common Pitfalls to Avoid
Do not use therapeutic-dose nadroparin (86 anti-Xa IU/kg twice daily) for colonoscopy bridging—this dramatically increases bleeding risk without benefit in stable post-PCI patients. 4
Do not continue aspirin through the colonoscopy—the combination of aspirin plus nadroparin significantly raises procedural bleeding risk, particularly if polypectomy is performed. 1
Do not give nadroparin within 12 hours of the procedure—inadequate clearance time increases bleeding complications. 1, 2
Do not delay restarting antiplatelet therapy beyond 48 hours post-procedure—prolonged interruption in post-PCI patients increases stent thrombosis risk. 1, 3