IbuprofenAnalgesicsAspirinAnti-Inflammatory Agents, Non-SteroidalCyclooxygenase InhibitorsAnalgesics, Non-NarcoticPlatelet Aggregation InhibitorsAcetaminophenNaproxenThromboxane B2DiclofenacSalicylatesAntipyreticsCyclooxygenase 2 InhibitorsTiclopidinePlatelet AggregationDuctus Arteriosus, PatentDouble-Blind MethodIndomethacinDrug Therapy, CombinationProstaglandin-Endoperoxide SynthasesCyclooxygenase 1Sodium SalicylateThromboxanesKetoprofenTherapeutic EquivalencyPlatelet Function TestsDose-Response Relationship, DrugBlood Platelets