Tieclopidine (53–32 C) belongs to a new series of synthetic compounds which have proved to inhibit significantly blood platelet aggregation in animals. Administered orally to rats, it reduces markedly the plate let aggregation induced by ADP and collagen. The activity appears 2 to 6 hours after a single dose and persists for 24 hours.The sludge and blood stasis induced in rats by protamin sulfate injections disappear completely in five minutes after an intravenous administration of Thieclopidine. Animals pretreated orally with this compound failed to show any sludge formation.The antithrombotic activity of Tieclopidine was demonstrated in rats carrying a dental broach implanted in the abdominal aorta. White thrombideveloped locally in the control animals, but were absent or much less severe in pretreated animals.In man the first clinical approach has shown that at a daily dose of 1 g the inhibitory effect of Tieclopidine on ADP induced aggregation requires 24 to 48 hrs to become significant and reaches a plateau after 5 or 6 days of treatment.
