Xopenex^® (levalbuterol hydrochloride) is a medication licensed to treat airway spasms that can be caused by asthma attacks and chronic obstructive pulmonary disease (which includes chronic bronchitis and emphysema). The medication works by opening up the airways to allow more air to get into and through the lungs. In clinical studies, the drug started working within 10 to 17 minutes, and the effects lasted for five to six hours on average. The dosage of Xopenex that your healthcare provider prescribes will depend on factors such as your age, the severity of your problem, and other medications you are currently taking.