Which of the following statements regarding ticlopidine is TRUE?: (A) It blocks GpIIb/IIIa receptors on platelet membrane, (B) It prevents ADP mediated platelet adenylyl cyclase inhibition, (C) It inhibits thromboxane A2 synthesis in platelets, (D) It does not prolong bleeding time
Answer is B. Abciximab, eptifibatide and tirofiban inhibits GpIIb/IIIa receptors. Ticlopidine and clopidogrel inhibits ADP receptors. Aspirin inhibits TXA2 synthesis in platelets. Bleeding time is prolonged by antiplatelet drugs whereas PT is prolonged by oral anticoagulants and aPTT by heparin.