Institut für Pharmakologie, Heinrich-Heine-Universität Dusseldorf, Moorenstr 5, D-40225, Düsseldorf, Germany, Tel: (211) 311-2500, Fax: (211) 311-4781.
Platelets. 1993;4(5):252-61. doi: 10.3109/09537109309013225.
Ticlopidine and clopidogrel are two thienopyridines with potent and apparently irreversible platelet inhibitory properties. The antiplatelet effects are mainly directed against ADP-induced stimulation of platelet function, in particular ADP-induced inhibition of adenylyl cyclase stimulation. There is evidence for additional effects, including inhibition of agonist-induced intracellular Ca(++) mobilization, interference with GpIIb/IIIa receptor/agonist interaction and inhibition of α-granule secretion. However, these actions are probably secondary to the ADP-antagonistic action. Thienopyridines do not directly interfere with arachidonic acid metabolism. The substances are inactive in vitro and have to undergo some form of bioactivation in vivo which requires 3 to 5 days of treatment for a maximum effect. The nature of the postulated active metabolite(s) is still unknown. From a pharmacological point of view, thienopyridines may be considered interesting alternatives to acetylsalicylic acid with particular value in shear-stress-mediated platelet activation, for example in prevention of acute thrombembolic risk in injury-related vessel stenosis.
噻氯匹定和氯吡格雷是两种噻吩并吡啶类药物，具有强大且明显不可逆的血小板抑制作用。抗血小板作用主要针对 ADP 诱导的血小板功能刺激，特别是 ADP 诱导的腺苷酸环化酶刺激抑制。有证据表明存在其他作用，包括抑制激动剂诱导的细胞内 Ca(++)动员、干扰 GpIIb/IIIa 受体/激动剂相互作用和抑制α-颗粒分泌。然而，这些作用可能继发于 ADP 拮抗作用。噻吩并吡啶类药物不会直接干扰花生四烯酸代谢。这些物质在体外无活性，必须在体内经过某种形式的生物活化，治疗 3 至 5 天才能达到最大效果。假定的活性代谢物的性质仍不清楚。从药理学的角度来看，噻吩并吡啶类药物可能被视为乙酰水杨酸的有趣替代品，在剪切应力介导的血小板激活中具有特殊价值，例如在损伤相关血管狭窄的急性血栓栓塞风险预防中。
