When should the Aggrastat (tirofiban) drip be stopped before surgery?

Perioperative Management of Aggrastat (Tirofiban) Before Surgery

Aggrastat (tirofiban) should be discontinued at least 2 to 4 hours before surgery to limit blood loss and transfusions. 1

Pharmacology and Timing Considerations

Tirofiban is a short-acting intravenous glycoprotein IIb/IIIa inhibitor with an elimination half-life of approximately 2 hours. Its pharmacodynamic effects are consistent with this timeframe:

• ADP-induced platelet aggregation returns to near-baseline levels within 4-8 hours after stopping the infusion 2
• The American College of Cardiology Foundation/American Heart Association guidelines specifically recommend discontinuing short-acting glycoprotein IIb/IIIa inhibitors (tirofiban or eptifibatide) at least 2-4 hours before surgery 1

Timing Protocol Based on Bleeding Risk

The timing of discontinuation should be guided by the bleeding risk of the procedure:

Standard Recommendation (All Surgeries)

• Discontinue tirofiban at least 2-4 hours before surgery 1

High Bleeding Risk Procedures

• Consider extending the discontinuation time to 4 hours to ensure complete clearance
• This allows approximately 2 elimination half-lives to pass, significantly reducing antiplatelet effects

Low Bleeding Risk Procedures

• The minimum 2-hour discontinuation period may be sufficient
• However, extending to 4 hours provides greater assurance of normalized platelet function

Comparison with Other Antiplatelet/Anticoagulant Agents

It's important to note that tirofiban has a much shorter discontinuation window compared to other antithrombotic medications:

• Abciximab (another glycoprotein IIb/IIIa inhibitor): discontinue at least 12 hours before surgery 1
• Clopidogrel and ticagrelor: discontinue 5 days before elective surgery 1
• Prasugrel: discontinue 7 days before elective surgery 1
• Unfractionated heparin (IV): discontinue ≥4 hours before surgery 1

Post-Operative Resumption

While the question focuses on preoperative discontinuation, it's worth noting that resumption of antiplatelet therapy should be carefully timed:

• For most patients, antiplatelet therapy can be resumed 24 hours after surgery if hemostasis is adequate 3
• In high bleeding risk procedures, consider delaying resumption for 48-72 hours 1

Clinical Considerations and Pitfalls

Common Pitfalls to Avoid

1. Insufficient discontinuation time: Failing to stop tirofiban at least 2-4 hours before surgery can increase bleeding risk
2. Excessive discontinuation time: Unnecessarily prolonged discontinuation may increase thrombotic risk in high-risk patients
3. Failure to account for renal function: Patients with renal impairment may require longer discontinuation periods due to delayed clearance

Special Circumstances

• Emergency surgery: If surgery cannot be delayed, be prepared for increased bleeding risk and consider platelet transfusions if clinically significant bleeding occurs
• High thrombotic risk patients: The risk-benefit ratio should be carefully considered, but the 2-4 hour window remains appropriate given tirofiban's short half-life

Conclusion

The evidence clearly supports discontinuing tirofiban 2-4 hours before surgery, with the exact timing dependent on the bleeding risk of the procedure and the patient's thrombotic risk profile. This timeframe allows for sufficient clearance of the drug while minimizing the period of increased thrombotic risk.