[Clinical evaluation of the control of antiplatelet therapy through platelet aggregation rate on polycythemia vera associated with thrombocytosis and erythromelalgia].

A 60-years-old woman with polycythemia vera with marked thrombocytosis and intolerable erythromelalgia was presented. A single dose of 400 mg aspirin was effective to improve the pain and cyanosis. And we studied the relationship between platelet aggregation rate and symptoms after administration of several antiplatelet drugs. A single dose of 100, 200, 400 and 800 mg aspirin, 25 mg indomethacin (Id), 200 mg OKY-046, and daily dose of 300 and 600 mg dipyridamole (Dp) and 300 mg ticlopidine (Tc) were given. Aspirin, Id and OKY-046 were effective for the improvement of finger pain. The complete inhibition of spontaneous aggregation (SPA) and aggregation by 2.0 micrograms/ml of collagen were well parallel with the improvement of symptoms. But duration of effect of LKY-046 were only 6 hours. Dp and Tc were not effective for the improvement of pain, had no relation with platelet aggregation rate. The concentration level of aspirin in vivo which suppresses the platelet aggregation induced by SPA and 2.0 micrograms/ml of collagen coincided well with the concentration level of this drug which suppresses the same platelet aggregation in vitro. It seems to be useful to suppress the platelet aggregation induced by SPA and 2.0 micrograms/ml of collagen with aspirin and Id for controlling the platelet aggregation induced circulatory disturbance in patient with thrombocytosis.