AspirinSensitivity and SpecificityPlatelet Aggregation InhibitorsAnti-Inflammatory Agents, Non-SteroidalBiotransformationTiclopidineProdrugsDose-Response Relationship, DrugChromatography, High Pressure LiquidPlatelet AggregationThromboxane B2Cyclooxygenase InhibitorsDrug InteractionsPlatelet Function TestsSalicylatesAdministration, OralDrug Therapy, CombinationTime FactorsArea Under CurveMicrosomes, LiverCamptothecinBlood PlateletsHalf-LifeIsoxazolesCytochrome P-450 Enzyme SystemDrug ResistanceThiophenesSodium SalicylateGlucuronidesChromatography, LiquidDouble-Blind MethodCytochrome P-450 CYP2D6Cross-Over Studies