Inhaled anticholinergic agents work via local muscarinic receptor blockade, causing relaxation of of airway smooth muscle and decreased airflow obstruction.
Benefits of inhaled bronchodilators include symptomatic improvement in COPD, reduction in exacerbations by 13-25% and modestly improves forced expiratory volume in the first second of expiration.
None of inhaled anticholinergics slow progressive decline of FEV1 over time or improve survival.