ABSTRACT
In most patients, platelet cyclooxygenase can be inhibited by aspirin doses as small as 30 mg per day. In clinical trials, aspirin doses ranging from 1,200 mg to 30 mg daily have been shown to be effective for prevention of thrombosis. Gastrointes tinal side-effects are diminished by the lower doses. Currendy, the recommended dosage of aspirin is 80 - 325 mg/day. Aspirin is rapidly metabolized by the liver, and when the drug is taken in low doses, most platelet inhibition occurs in the portal vein. Since the platelet inhibition lasts the life of the platelet, the biological half-life of aspirin is considerably longer than the plasma half-life.
