Antiplatelet drugs cyclooxygenase inhibitors

Aspirin produces an antipyretic and anti-inflammatory effect primarily by irreversibly inhibiting cyclooxygenase (thus having similar effects to NSAIDs). It possesses an antiplatelet effect that may have additive effect with other drugs with a similar effect (e.g, selective serotonin reuptake inhibitors) and those which affect other aspects of blood clotting. The risk of interactions and adverse effects are reduced by using a lower dose (e.g. 75 mg) fortunately, a full antiplatelet effect is seen at this dose. This is considered in Part 1, Cardiovascular Drugs. 

Most NSAIDs are nonselective inhibitors of cyclooxygenases, acting on both COX 1 and COX 2 isoforms to decrease formation of PGs and thromboxanes. This action is a primary (but not sole) contributor to the pharmacologic actions of NSAIDs. These actions include analgesic, antipyretic, anti-inflammatory, and antiplatelet effects. Acetylsalicylic acid (ASA) is the prototype of the group, which includes more than 20 individual drugs. 

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