Effect of pentoxifylline on platelet aggregation.

The effect of various concentrations of pentoxifylline, a methylxanthine, on platelet aggregation was evaluated in vitro by Born's method. The study was performed on platelet-rich plasma obtained from two series of clinically healthy subjects: in the first, pentoxifylline was added to platelet-rich plasma just before ADP or epinephrine; in the second, pentoxifylline was incubated with platelet-rich plasma for 150 minutes at 37 degrees C before testing. Statistical analysis of the results demonstrates that pentoxifylline exerts a dose-dependent inhibiting action on platelet aggregation, particularly when epinephrine is chosen as the aggregating agent, and that the pre-incubation of pentoxifylline with blood platelets greatly enhances its inhibitory effect.