Question

Which of the following statements about ticagrelor is TRUE?

• A. It is a reversible P2Y12 receptor inhibitor
• B. It is a prodrug requiring hepatic activation
• C. It causes more cerebral bleeding than clopidogrel
• D. It is given once daily

Hint:

The feature that separates ticagrelor from clopidogrel/prasugrel is reversible, direct binding.

Answer 1

The Correct Option is A

Step 1: Classify ticagrelor.
Ticagrelor is an antiplatelet agent of the cyclopentyltriazolopyrimidine (CPTP) class. It blocks the platelet P2Y12 ADP receptor, reducing ADP-mediated platelet aggregation.

Step 2: Key pharmacological feature.
Unlike the thienopyridines (clopidogrel, prasugrel) which bind the P2Y12 receptor irreversibly, ticagrelor binds reversibly. Hence option 1 is correct.

Step 3: Why the other statements are false.
• Prodrug - FALSE. Ticagrelor is directly active and does NOT require hepatic CYP activation (its active metabolite also contributes, but the parent drug is itself active). Clopidogrel and prasugrel are the prodrugs.
• More cerebral bleed than clopidogrel - In the PLATO trial, total major bleeding was similar; ticagrelor showed slightly more non-CABG/spontaneous bleeding but it is not characterised as causing distinctly more intracranial bleeding as a defining true feature. The unequivocally correct statement is reversibility.
• Once daily - FALSE. Because binding is reversible and its half-life is short, ticagrelor is given twice daily.

Key fact: Ticagrelor = directly-acting, reversible P2Y12 inhibitor, dosed twice daily; it also causes dyspnea (adenosine effect) and bradyarrhythmias.