The platelet function dose-response to incremental abciximab (Reopro, Eli Lilly/Centocor, Indianapolis, IN) bolus dosing during percutaneous coronary intervention (PCI) was evaluated in 85 patients using a point-of-service platelet function assay. Patients received incremental bolus doses of abciximab at 10- to 20-min intervals; platelet function was measured at 10-min intervals during dosing. The percentage of patients achieving : 80% inhibition of platelet function after 50%, 75%, and 100% of a standard abciximab bolus was 40%, 87%, and 95%, respectively. There were no significant associations between the platelet function dose-response to abciximab and age, weight, platelet count, hematocrit, heparin dose, peak activated clotting time, thienopyridine use prior to PCI, gender, cigarette smoking, diabetes mellitus, or clinical syndrome. This study demonstrated significant interpatient variability in platelet function dose-response to abciximab with a substantial proportion (87%) of patients achieving high-level platelet function inhibition with less than the standard abciximab bolus dose. (C) 2001 Wiley-Liss, Inc.