Switching between P2Y12 inhibitors: Rationale, methods, and expected consequences

The pharmacological and clinical differences of the three recommended oral P2Y12 inhibitors (clopidogrel, prasugrel, ticagrelor) enable physicians to switch from one agent to another that it is considered more appropriate in the specific clinical setting. Moreover, the recent availability of cangrelor, the only intravenous P2Y12 inhibitor with a rapid onset and offset of its antiplatelet action, makes it necessary to switch from this agent to an oral P2Y12 inhibitor for a continued platelet inhibition after percutaneous coronary intervention. Several pharmacodynamic studies have provided information on how to change drug, in terms of timing and dosage, without running the risk of a temporary impairment of platelet inhibition. In addition, several studies have assessed the impact of the switching between P2Y12 inhibitors on clinical outcomes. Overall, these evidences have prompted the development of an extensive expert consensus document, have set the basis for recent practice guidelines recommendations, and have stimulated several systematic overviews. The present article provides a brief and schematic summary on the topic of switching between P2Y12 inhibitors, focusing on three main practical issues: why and how to switch therapies and what are the clinical consequences of such strategy.