List of products in the National Drug Code with proprietary name . Metaproterenol is used to treat wheezing and shortness of breath from lung problems (e.g., asthma, chronic obstructive pulmonary disease, bronchitis, emphysema). Controlling these symptoms can decrease time lost from work or school. Metaproterenol 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. This drug is also known as orciprenaline in other countries.