Ticlopidine administration to patients does not inhibit the ability of their monocytes to form rosettes and to phagocytize erythrocytes in vitro.

Inhibition of monocyte function is known to have important clinical consequences and to be present in a variety of diseases: Accordingly we evaluated the effect of Ticlopidine, a powerful and widely employed inhibitor of platelet aggregation, on the capacity of peripheral blood monocytes to ingest IgG-coated erythrocytes. Our results show that in vivo administration of this drug has no effect on monocyte phagocytosis, when tested with an in vitro assay. This finding suggests that Ticlopidine can be safely used in patients with depressed monocyte function and in those in whom an impairment of monocyte phagocytosis could lead to a deterioration of the clinical picture.