Muscarinic antagonists inhibit secretions and relax smooth muscle in the respiratory system. The parasym-pathetic innervation of respiratory smooth muscle is most abundant in large airways, where it exerts a dominant constrictor action. In agreement with this innervation pattern, muscarinic antagonists produce their greatest bronchodilator effect at large-caliber airways.

By this mechanism they can block reflex laryngospasm during surgery. In addition, these drugs are potent inhibitors of secretions throughout the respiratory system, from the nose to the bronchioles.

Coping with Asthma

Coping with Asthma

If you suffer with asthma, you will no doubt be familiar with the uncomfortable sensations as your bronchial tubes begin to narrow and your muscles around them start to tighten. A sticky mucus known as phlegm begins to produce and increase within your bronchial tubes and you begin to wheeze, cough and struggle to breathe.

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