Anticholinergics are a group of drugs used to counteract a chemical in the body (acetylcholine) and relax certain muscles.  Some types of anticholinergics are inhaled to treat asthma. The drugs are breathed either into the lungs (through an inhaler or nebulizer), or into the sinuses (through a nasal spray).

The anticholinergics used to treat asthma are considered bronchodilators, medications used to open bronchial tubes to improve breathing. They are primarily used to treat the breathing-related symptoms of an allergic reaction or asthma attack.

Fast-acting bronchodilators (specifically beta agonists) work more quickly than anticholinergics, which generally take at least 15 minutes. However, anticholinergics last longer, usually 3 to 4 hours. Anticholinergics were once used as a rescue medication for asthma because they were the fastest treatment available. Today, they are usually combined with beta-agonists for asthma treatments or taken in the form of a nasal spray for the treatment of allergic rhinitis.

There are a range of anticholinergics that are used to treat a number of medical conditions, such as Parkinson’s disease and irritable bowel syndrome. However, the types of anticholinergics usually used to treat allergy and asthma symptoms are ipratropium, atropine and glycopyrrolate.

Anticholinergics have potential side effects (e.g., drowsiness, rapid heartbeat, dryness) and may not be recommended in people with certain conditions (e.g., urinary disease, high blood pressure). While anticholinergics are a very effective form of treatment, anyone interested in this medication should consult a physician.