The effect of dipyridamole on platelet function: correlation with blood levels in man

1 The effect on platelet functions of dipyridamole (a pyrimido-pyrimidine compound) was compared with a control group of patients taking warfarin. 2 Adhesion, aggregation and platelet factor 4 availability showed a significant decrease in the dypyridamole group. 3 Aggregation and platelet factor 4 showed a significant correlation with blood dipyridamole level. 4 Adhesion, aggregation and platelet factor 4 were reduced below the lower limit of normal at blood dipyridamole levels above 3.5 micronmol/1.