Levodropropizine

Levodropropizine has affinity for H1-histaminic and alpha-adrenergic receptors. ^[1]

Levodropropizine has weaker central sedative effects than the racemate and it does not induce physical dependence in rats. ^[1] Levodropropizine (15 mg/kg, i.v.) reduces both the duration of apnoea and the response of the C-fibre to phenylbiguanide. The LVDP-induced inhibition of the C-fibre response to PBG is on average 50% in pulmonary and 25% in non-pulmonary fibres. ^[2] Levodropropizine is shown to have good antitussive activity in anaesthetized guinea-pigs and rabbits. Levodropropizine (i.v.) is 1/10 to 1/20 as active as codeine and comparable to dropropizine on mechanically and electrically induced coughing in rabbits and guinea-pigs. Levodropropizine (orally) is comparable with those of both dropropizine and codeine against coughing induced by irritant aerosols. ^[3] Levodropropizine (40 μg/50 μL i.c.v.) does not prevent electrically-induced cough, while Codeine (5 μg/50 μl i.c.v.) markedly prevents coughing in guinea-pigs. Levodropropizine has a peripheral site of action which is related to sensory neuropeptides. ^[4] Levodropropizine (10 mg/kg, 50 mg/kg and 200 mg/kg) reduces in a dose-dependent manner the extravasation of Evans blue dye evoked by capsaicin in the rat trachea. Levodropropizine (200 mg/kg) inhibits also substance P-evoked extravasation, whereas it does not affect the extravasation evoked by platelet activating factor. ^[5]