Platelet aggregation after naftidrofuryl application in vitro and ex vivo.

Naftidrofuryl has been shown to inhibit the interaction between platelets and damaged endothelium, which may lead to thrombosis and is mediated by the 5-hydroxytryptamine. (5-HT2) receptor. This study was designed to investigate the effects of naftidrofuryl on 5-HT induced platelet aggregation.

Naftopidil inhibits 5-hydroxytryptamine-induced platelet aggregation and 5-hydroxytryptamine uptake in platelets of healthy volunteers.

Naftopidil exerts its antihypertensive action via alpha 1-adrenoceptor blockage and Ca2+ antagonism in vascular smooth muscle. Since the chemically similar 1-(1-naphthyl) piperazine is known to be a 5-hydroxytryptamine2 receptor antagonist, the 5-hydroxytryptamine (5-HT) antagonistic properties of naftopidil were tested by examining 5-HT-induced aggregation and 5-HT uptake in platelets from 12 healthy volunteers after oral administration of 60 mg naftopidil or placebo. Platelet aggregation in vitro was inhibited by naftopidil with a Ki value of 1.