General pharmacology of the new antitussive levodropropizine.

The general pharmacological profile of levodropropizine (S(-)3-(4-phenyl-piperazin-1-yl)-propane-1,2-diol, DF 526), a new antitussive drug, was compared with that of dropropizine racemate. Levodropropizine had weaker central sedative effects than the racemate and it did not induce physical dependence in rats. When given intravenously or intraperitoneally, levodropropizine did not exert any significant effects on the cardiovascular and respiratory systems. Receptor binding data excluded interaction with beta-adrenergic, muscarinic and opiate receptors. On the contrary, levodropropizine has affinity for H1-histaminic and alpha-adrenergic receptors. The affinity was also confirmed with isolated organ preparations. On the basis of this study, levodropropizine appears to have a better tolerability index than the racemate.