Acute and Chronic Effects of Oral Erdosteine on Ciliary Beat Frequency, Cough Sensitivity and Airway Reactivity

Erdosteine as a mucolytic agent that decreases mucus viscosity and facilitates mucus expulsion from the airways by cough or ciliary movement. Our objective was to determine whether erdosteine can directly contribute to mucus clearance. We addressed the issue by monitoring acute and chronic effects of erdosteine on ciliary beat frequency (CBF), cough sensitivity, and airway smooth muscle reactivity. The experiments were performed in healthy guinea pigs. Erdosteine (10 mg/kg) was administrated orally in a single dose or daily through 7 days. The cough reflex and specific airway resistance were evaluated in vivo. The CBF in tracheal brushed samples and the contractile response of tracheal smooth muscle stripes to bronchoconstrictive mediators were evaluated in vitro. We found that neither acute nor chronic erdosteine treatment had a significant effect on cough sensitivity and airway reactivity. However, in the vitro condition, erdosteine increased CBF and reduced tracheal smooth muscle contractility; the effects were more pronounced after chronic treatment. We conclude that erdosteine may directly contribute to mucus clearance by CBF stimulation. Although erdosteine has no effect on cough reflex sensitivity, its mild bronchodilator and mucolytic properties may promote effective cough.