What are the risks of missing one dose of Brillinta (ticagrelor)?

Risks of Missing One Dose of Ticagrelor (Brilinta)

Missing a single dose of ticagrelor (Brilinta) increases the risk of stent thrombosis and cardiovascular events due to reduced platelet inhibition, especially in patients with recent acute coronary syndrome or coronary stent placement.

Understanding Ticagrelor and Its Importance

Ticagrelor is a potent, reversible P2Y12 receptor inhibitor that prevents platelet aggregation. It is prescribed for:

• Acute coronary syndromes (ACS)
• After percutaneous coronary intervention (PCI) with stent placement
• Secondary prevention in high-risk cardiovascular patients

Unlike other antiplatelet medications, ticagrelor has several unique characteristics:

• Twice-daily dosing (90 mg twice daily)
• Faster onset of action compared to clopidogrel
• More potent platelet inhibition
• Reversible binding to P2Y12 receptors

Risks of Missing a Single Dose

Immediate Risks

• Reduced Platelet Inhibition: Ticagrelor's effect begins to diminish 8-12 hours after the last dose 1
• Increased Thrombotic Risk: The antiplatelet effect may decrease significantly if a dose is missed, particularly concerning for patients with:
  • Recently placed coronary stents
  • Recent ACS events
  • High GRACE risk scores

Specific Concerns Based on Time Since Event

1. Highest Risk Period (0-30 days post-ACS/PCI):

   • Missing even one dose during this period poses substantial risk
   • Stent thrombosis risk is highest during this window
   • May lead to acute myocardial infarction or death

2. Moderate Risk Period (1-12 months):

   • Still significant risk of thrombotic events
   • Reduced but not eliminated risk of stent thrombosis

3. Extended Therapy (>12 months):

   • Lower but still present risk of adverse events

What To Do If a Dose Is Missed

The guidelines from the American College of Cardiology/American Heart Association provide specific recommendations for ticagrelor management 1:

1. If remembered within 12 hours of the usual time:

   • Take the missed dose immediately
   • Resume regular twice-daily schedule

2. If more than 12 hours have passed:

   • Skip the missed dose
   • Take the next dose at the regularly scheduled time
   • Do not double the dose to make up for the missed one

3. If unsure when the dose was missed:

   • Take the next dose at the regular time
   • Contact healthcare provider if experiencing any symptoms

Special Considerations

• Twice-daily dosing: Unlike clopidogrel (once daily), ticagrelor's twice-daily regimen makes adherence more challenging 1
• Perioperative management: Discontinuation should occur at least 5 days before planned surgery 1
• Patients with history of stroke/TIA: Ticagrelor increases risk of intracranial hemorrhage compared to clopidogrel 1

Common Pitfalls to Avoid

1. Taking a double dose to compensate: This can increase bleeding risk without providing additional benefit
2. Switching between antiplatelet agents without medical supervision: Different P2Y12 inhibitors have different mechanisms and dosing schedules
3. Stopping ticagrelor abruptly: Can lead to rebound platelet activity and increased thrombotic risk
4. Poor adherence patterns: Missing doses regularly significantly increases cardiovascular risk
5. Failing to recognize symptoms: Chest pain, shortness of breath, or other symptoms after missing a dose should prompt immediate medical attention

Conclusion

Missing a single dose of ticagrelor can significantly increase thrombotic risk, particularly in high-risk patients and those within the first month after an ACS event or stent placement. Patients should be educated about the importance of medication adherence and have a clear plan for what to do if a dose is missed.