Monitoring ticlopidine for secondary prevention in patients with thrombotic infarction or TIA using platelet aggregation

Patients with ischemic cerebral infarction (except those with cerebral embolism) were retrospectively studied to determine the relationship between the prevention of recurrence and inhibition of platelet aggregation by ticlopidine. The subjects comprised 68 patients, including 50 males and 18 females, aged 70.2 ± 9.2 years on average. We measured the platelet aggregation induced by adenosine diphosphate (ADP) during a mean period of 30.2 months. Cerebral infarction and TIA recurred in 15 patients during this period. The oral administration of ticlopidine (200 mg/day or 300 mg/day) resulted in a significant inhibition of ADP-induced platelet aggregation. In contrast, no difference in platelet aggregation was observed between the recurrent group and non-recurrent group either before or after the treatment. However, there was a significant cumulative difference favoring the lower group over the higher group, when were divided on the basis of the below 15% (