Switching From Ticagrelor or Prasugrel to Clopidogrel
Ticagrelor and prasugrel are newer antiplatelet drugs which, like clopidogrel, block the P2Y12 platelet receptor to inhibit platelet aggregation. Compared with clopidogrel, both ticagrelor and prasugrel have greater clinical efficacy but also have a higher risk of bleeding and are much more costly. Therefore, some institutions and providers switch patients from ticagrelor or prasugrel to clopidogrel in an effort to lower bleeding risk, stem costs, or otherwise ensure that patients can safely adhere to long-term P2Y12 inhibitor therapy. From a pharmacodynamic perspective, switching patients from ticagrelor or prasugrel to clopidogrel comes at a cost of less antiplatelet efficacy. However, it is unclear if antiplatelet efficacy is diminished enough to affect clinical outcomes. This is because clinical trial data investigating such a switch is scant, leaving the clinician unsure as to the acceptability of this practice. Current clinical trial data have thus far not shown any clinical detriment from switching from ticagrelor or prasugrel to clopidogrel, but there are many limitations to these investigations. So although a large-scale switch of patients from ticagrelor or prasugrel to clopidogrel is not recommended, if the patient is unable to adhere to long-term ticagrelor or prasugrel therapy, switching him/her to clopidogrel seems to be a reasonable practice to maintain chronic suppression of platelet aggregation and minimize the risk of ischemic events.