List of products in the National Drug Code with proprietary name . Levalbuterol is used to prevent and treat wheezing and shortness of breath caused by breathing problems (such as asthma, chronic obstructive pulmonary disease). It is a quick-relief drug. Levalbuterol belongs to a class of drugs known as bronchodilators. It works by relaxing the muscles around the airways so that they open up and you can breathe more easily. Controlling symptoms of breathing problems can decrease time lost from work or school.