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Ticagrelor has greater antiplatelet efficacy compared with clopidogrel, but may be accompanied by an increased risk of bleeding. This study evaluated the antiplatelet effect and pharmacokinetic profile of low-dose ticagrelor in healthy Chinese volunteers.
Thirty healthy subjects were randomized to receive standard-dose ticagrelor (180-mg loading, 90-mg twice daily [bid] [n=10]), low-dose ticagrelor (90-mg loading, 45-mg bid [n=10]), or clopidogrel (600-mg loading, 75-mg once daily [n=10]). Platelet reactivity was assessed using the VerifyNow P2Y12 assay at baseline, 0.5, 1, 2, 4, 8, 24, 48, and 72 hours post-dosing. Concentrations of ticagrelor and AR-C124910XX were measured for pharmacokinetic analysis.
The percent inhibition of P2Y12 reaction units was higher in the low-dose and standard-dose ticagrelor group than in the clopidogrel group at the 0.5, 1, 2, 4, 8, 48 hours post-dosing (P<0.05 for all), but did not differ significantly between the two ticagrelor doses at any time-point (P>0.05). Plasma concentrations of ticagrelor and ARC124910XX were approximately 2-fold higher with standard-dose versus low-dose ticagrelor. Both ticagrelor doses were well tolerated and no serious adverse event was observed.
In conclusion, in healthy Chinese subjects, low-dose ticagrelor achieved faster and greater inhibition of platelet function compared with clopidogrel, with a similar antiplatelet efficacy to standard-dose ticagrelor.