Low- vs High-Dose Aspirin

Abstract

• Low-dose aspirin may be inadequate for inhibition of platelet function in hyperlipoproteinemics due to increased platelet reactivity. Platelet function was studied in 18 type II hyperlipoproteinemic and 12 normal subjects after at least ten days of treatment with placebo and with low-dose (0.45 mg/kg/day) and high-dose (900 mg/day) aspirin. In the normal and hyperlipoproteinemic subjects, low-dose aspirin produced near maximal (90%) inhibition of platelet thromboxane generation, significant prolongation of the bleeding time, and significant inhibition of platelet aggregation, similar in degree to the inhibition produced by high-dose aspirin. There was no significant difference between hyperlipoproteinemic and normal subjects in any of the platelet function measures before and after aspirin treatment. Thus, a daily 0.45-mg/kg aspirin dose (20 to 45 mg) effectively inhibited platelet function in type II hyperlipoproteinemics, who do not appear to have an increased dose requirement for aspirin. (<i>Arch Intern Med</i>1986;146:921-925)