Summary
The interactions of oral and i.v. administrations of corticosteroids with the effects
of ticlopidine were studied, in a search for an antidote for possible excessive prolongations
of bleeding time induced by antiaggregating agents. Indeed, the results show that
an i.v. injection of methylprednisolone or an oral treatment with prednisolone counteract
the prolongation of bleeding time but do not interfere with the inhibition of platelet
aggregation brought about by ticlopidine. This could be ascribed to a vasoconstrictive
effect of corticosteroids, possibly through reduction of vascular prostacyclin release.
If this mode of action was confirmed, this useful finding would essentially apply
to ticlopidine, but not to cyclooxygenase inhibitors such as aspirin which, by themselves,
abolish prostacyclin production.
Keywords
Ticlopidine - Corticosteroids - Bleeding time prolongation - Platelet aggregation
