What is ipratropium and how does it differ from albuterol?

Ipratropium is a short-acting anticholinergic bronchodilator that works by blocking muscarinic receptors in airway smooth muscle, reducing bronchoconstriction and mucus secretion. It is slower in onset than albuterol, taking 15 to 30 minutes to work, but lasts longer at 6 to 8 hours. Ipratropium is often combined with albuterol in nebulizer treatments for acute exacerbations of chronic obstructive pulmonary disease and severe asthma attacks because the two drugs work through different mechanisms. Tiotropium is the long-acting version used as a daily maintenance medication for COPD.