Evaluation of Effectiveness of Anti-Platelet Medicines with Respect to Bleeding Time

We examined the relationship between bleeding time and anti-platelet medicines prescribed to 472 ischemic heart disease patients in Gifu Prefectural Gifu Hospital. The average bleeding time of the patients taking aspirin (81-200 mg) and ticlopidine (100-200 mg) concomitantly was significantly longer than that of those in the control group, while that for patients taking aspirin alone or cilostazol (100-200 mg) and aspirin concomitantly was not significantly different from that of control. There was no significant correlation between the dosage (mg/kg) of each medicine and the bleeding time. In 14 patients, the bleeding time was not prolonged when the administration of platelet medicines was started or additional antiplatelet medicines were given. The presence of patients who did not respond to anti-platelet medicines, and the difficulty of achieving reproducibility in measured bleeding times might have lead to the absence of a significant correlation between the dosage of medicines and the bleeding time. Our findings therefore suggest that it may be difficult to evaluate the effectiveness of adjusting dosages of anti-platelet medicines from the bleeding time.