Antitussive effect of diltiazem in experimental conditions.

Cough is the most important defence reflex of the airways. Little information exists about participation of the ion channels in the mechanism of the cough reflex. The aim of the study was to investigate the effect of diltiazem administration on the sensitivity of the mechanically induced cough reflex in experimental conditions. Mechanical stimulation of the laryngopharyngeal and tracheobronchial area of the airways in non-anaesthetized cats was used in this experiment. The number of cough efforts, and the frequency and intensity of the cough attack were utilized as evaluated parameters. Perorally administered diltiazem (30 mg/kg b.w.) caused a statistically significant decrease of measured cough parameters. Cough - suppressing activity of diltiazem was lower than codeine, but higher than dropropizine and prenoxdiazine. Experimental results showed antitussive activity of the calcium-channel blocker diltiazem and suggested the role of voltage-gated calcium channels of type L in mechanism of the cough reflex. (Fig. 4, Ref. 15.).