Specific inhibition of ADP-induced platelet aggregation by clopidogrel in vitro. Author A A Weber, S Reimann, K Schrör Journal. British Journal of Pharmacology SCI(E) SCOPUS The thienopyridine clopidogrel is a specific inhibitor of ADP-induced platelet aggregation ex vivo. No direct effects of clopidogrel (⩽100 μ M) on platelet aggregation in vitro have been described so far. NAVER Academic Specific inhibition of ADP‐induced. Abstract. The thienopyridine clopidogrel is a specific inhibitor of ADP-induced platelet aggregation ex vivo. No direct effects of clopidogrel (⩽100 μM) on platelet aggregation in vitro have been described so far.Possible in vitro antiaggregatory effects (turbidimetry) of clopidogrel were studied in human platelet-rich plasma and in washed. Specific inhibition of ADP-induced platelet aggregation by clopidogrel in vitro 1Artur-Aron Weber, 1Stephanie Reimann & *,1 Karsten Schro¨r 1Institut fu¨r Pharmakologie, Heinrich-Heine-Universita¨tDu¨sseldorf, Germany Abstract. The thienopyridine clopidogrel is a specific inhibitor of ADP-induced platelet aggregation ex vivo. No direct effects of clopidogrel (100 μ M) on platelet aggregation in vitro have been described so far. E-Mail Address. Password. Forgotten Password? Remember Me Results. Adenosine diphosphate (ADP, 30 µ m)-induced platelet responses were almost completely inhibited by clopidogrel. After discontinuation of the drug, platelet function gradually increased and complete recovery was seen 7 days after the last clopidogrel dose. What had been shown was that they were potent inhibitors of ADP-induced platelet aggregation, but the P2Y 12 receptor had not been identified. Furthermore, it was clear that ticlopidine and clopidogrel were prodrugs which means they are inactive in-vitro and therefore need metabolism to be activated in-vivo. The thienopyridine clopidogrel is a specific inhibitor of ADP‐induced platelet aggregation ex vivo. No direct effects of clopidogrel (100 μ M) on platelet aggregation in vitro have been described so far.