[Tiotropium as a controller of bronchoconstriction].

Cholinergic nerve fibres arise in the nucleus ambiguus and the dorsal motor nucleus of the vagus nerve in the brainstem. They travel down as the vagus nerve to parasympathetic ganglia placed in the walls of the airways. From these ganglia, short postganglionic fibres innervate airway smooth muscle and the submucosal glands in the lung. Activation of vagal nerve releases acetylcholine at the neuroeffector junctions, where it binds to postsynaptic receptors, resulting in bronchoconstrictions. The resting bronchomotor tone in normal airways has a cholinergic component mediated via muscarinic cholinergic receptors. The human airways have five subtypes of muscarinic cholinergic receptors: the M1 and M3 mediate bronchoconstriction and stimulation of mucus secretion, while M2 control the release of acetylcholine from M1 and M3 receptors through a negative-feedback mechanism. Anticholinergic bronchodilators act by blocking muscarinic receptors. Tiotropium bromide is cutting age anticholinergic bronchodilator. It dissociates more slowly from M1 and M3 than from M2 receptors and subsequently has a long and safety duration of action. In COPD patients tiotropium comparing to placebo, ipratropium and long acting beta agonists significantly improves lung function. It is an effective bronchodilator that reduces dyspnea, COPD exacerbations frequency and improves health status. This suggests that tiotropium will make an important contribution to chronic pulmonary disease therapy.