There are two main types of bronchodilators:

• Long-Acting Bronchodilators - Because long-acting bronchodilators do not work as quickly as short-acting bronchodilators, they are not used to treat acute or sudden symptoms. People take them daily to prevent symptoms from developing, and the effects can last for up to 24 hours.
• Short-Acting Bronchodilators - Short-acting bronchodilators are often referred to as rescue inhalers as they treat symptoms that come on suddenly, including chest tightness, wheezing, and shortness of breath (dyspnea). Short-acting bronchodilators work quickly, usually within a few minutes; however, their therapeutic effects generally only last around four to five hours.