HEMOSTASEOLOGIC AND HEMATOLOGIC PARAMETERS WITH ASPIRIN AND TICLOPIDINE TREATMENT IN PATIENTS WITH CEREBROVASCULAR-DISEASE - A CROSS-OVER STUDY

No direct comparisons of the effects of ticlopidine and aspirin on pla telet aggregability, clotting parameters, and blood count are availabl e in a cross-over study design in humans. We investigated 45 patients with cerebrovascular disease. Twenty-one patients received 300 mg aspi rin once daily for 2 weeks and then for 2 more weeks received 250 mg t iclopidine twice daily. In 24 other patients, the scheme was reversed. ADP-induced aggregability was lower during ticlopidine treatment; epi nephrine- and collagen-induced aggregabilities were lower with aspirin treatment. Platelet counts were higher during ticlopidine than during aspirin treatment (199.6/nl with aspirin, 213.0/nl with ticlopidine, p = 0.008), probably reflecting less platelet activation and degradati on and a longer platelet survival time induced by ticlopidine treatmen t.