From the Guidelines
The recommended protocol for transitioning from ticagrelor to prasugrel involves discontinuing ticagrelor for 24 hours before administering the loading dose of prasugrel (60 mg). This approach is based on the practical algorithm for switching between oral P2Y12 inhibitors provided in the 2017 ESC update 1, which recommends a 24-hour interval between the last dose of ticagrelor and the initiation of prasugrel to avoid gaps in the inhibitory effects of these medications.
Key Considerations
- The transition protocol is designed to minimize the risk of bleeding and thrombotic events by allowing adequate clearance of ticagrelor before initiating prasugrel.
- The 24-hour waiting period is necessary due to the pharmacodynamic profiles of these medications, with ticagrelor being a reversible P2Y12 inhibitor and prasugrel being an irreversible inhibitor.
- Aspirin therapy should typically be continued without interruption during the transition period if the patient is on dual antiplatelet therapy, as recommended by the ACC/AHA and ESC guidelines 1.
Transition Protocol
- Discontinue ticagrelor for 24 hours
- Administer the loading dose of prasugrel (60 mg) after the 24-hour waiting period
- Follow the loading dose with the maintenance dose of 10 mg daily (or 5 mg daily for patients ≥75 years old, <60 kg, or with history of stroke/TIA)
Monitoring
- Patients should be monitored for both bleeding and thrombotic events during the transition period, as the risk of these events may be increased during the transition from one P2Y12 inhibitor to another 1.
From the Research
Transitioning from Ticagrelor to Prasugrel
There is limited direct evidence on the recommended protocol for transitioning from ticagrelor to prasugrel. However, some studies provide insights into the pharmacodynamics and safety of switching between different P2Y12 inhibitors.
- Pharmacodynamic Considerations: A study 2 found that switching directly from clopidogrel to prasugrel resulted in greater inhibition of platelet aggregation, with maximal platelet aggregation decreasing from 39% to 12% by 30 minutes and to 5% by 1 hour after a prasugrel 60 mg loading dose.
- Safety and Efficacy: Another study 3 investigated the onset of optimal P2Y12-ADP receptor blockade after ticagrelor and prasugrel intake in non-ST elevation acute coronary syndrome. The results showed that optimal platelet reactivity inhibition was obtained 2 hours after the loading dose in both groups, with maximal inhibition reached after 4 hours.
- Clinical Outcomes: While there is no direct evidence on transitioning from ticagrelor to prasugrel, a study 4 found that early dual-antiplatelet therapy with ticagrelor was superior to clopidogrel at 1 year in reducing recurrent stroke in CYP2C19 loss-of-function carriers with stroke or TIA.
Key Points to Consider
- The transition from ticagrelor to prasugrel may require careful consideration of the patient's individual risk factors and clinical status.
- The pharmacodynamic profiles of ticagrelor and prasugrel suggest that switching between these agents may not require a washout period.
- However, the safety and efficacy of transitioning from ticagrelor to prasugrel have not been extensively studied, and more research is needed to inform clinical practice.