AspirinPlatelet Aggregation InhibitorsThromboxane B2Platelet AggregationAnti-Inflammatory Agents, Non-SteroidalTiclopidineDrug Therapy, CombinationBlood PlateletsDouble-Blind MethodDose-Response Relationship, DrugCyclooxygenase InhibitorsSalicylatesPlatelet Function TestsTreatment OutcomeDrug Administration ScheduleSodium SalicylateFibrinolytic AgentsHemorrhageAnticoagulantsAsthma, Aspirin-InducedWarfarinTablets, Enteric-CoatedCyclooxygenase 1Gastrointestinal HemorrhageBleeding TimePlatelet ActivationTime FactorsProstaglandin-Endoperoxide SynthasesThromboxanesIbuprofenProspective StudiesThromboxane A2ThrombosisRisk FactorsCyclooxygenase 2 Inhibitors