Ipratropium

Ipratropium bromide is another drug approved for the treatment of asthma.

Marketed as Atrovent, Apovent, and Aerovent, ipratropium bromide is in a class of drugs known as anticholinergics. It is normally prescribed for the treatment of chronic obstructive pulmonary disease (COPD) and severe asthma. These diseases are characterized by constricted airways (bronchi), which cause reduced airflow into the lungs

It may be useful for the control of the bronchial constriction associated with allergy-induced asthma, although it does little to relieve the classic symptoms of allergic rhinitis, or “hay fever.” It does not reduce nasal congestion, for instance, although it may reduce the symptoms of runny nose that sometimes accompany allergic rhinitis.

Anticholinergic Activity

Ipratropium bromide works by binding with muscarinic acetylcholine receptors on the smooth muscle cells of the bronchi. This prevents these cells from contracting, thus preventing airway constriction. 

When used to treat asthma, it is often combined with another drug, such as albuterol or fenoterol, and delivered into the lungs using a metered-dose inhalation device (an inhaler). Ipratropium may also be delivered as an aerosol with a nebulizer (a device that delivers a mist to be inhaled). Inhalers and nebulizers are normally used three to four times per day, or once every six to eight hours. Ipratropium bromide is considered a short-acting bronchodilator.

Side Effects

Side effects and contraindications are minimal, at least when inhaled.

People who are allergic to atropine should avoid ipratropium bromide and other anticholinergic drugs. Ipratropium bromide is derived from atropine, a plant-derived drug, but since it is such a large molecule, it does not cross the blood-brain barrier and thus does not affect the central nervous system. 

Inhalation of anticholinergic drugs significantly reduces the chance that they will be associated with typical side effects, such as dry mouth, sedation (sleepiness), skin flushing, racing or irregular heartbeat, or nausea, although any of these can occur in rare instances.

Ipratropium bromide is also marketed in combination with other asthma drugs, such as the bronchodilator, theophylline, or drugs in a class known as beta-adrenergic agonists.

In theory, at least, simultaneously using other anticholinergic drugs or drugs with anticholinergic activity—such as older, tricyclic antidepressants, anti-Parkinson drugs, or the heart drug quinidine—could increase the risk of side effects.

Care should be taken to avoid getting ipratropium bromide in the eyes. Narrow angle glaucoma is one potential side effect of eye exposure. Call your doctor immediately if you get the drug in your eyes, or if you experience blurry vision, or other symptoms of changes in the eyes or vision.

Limited Evidence for Effectiveness against Allergies

A recent report by British researchers reviewed all available published data regarding the effectiveness of ipratropium bromide for the treatment of hay fever.

Investigators noted that there have been no randomized, controlled trials addressing this specific question. The scientists could reach no conclusions, therefore, regarding the use of the anticholinergic drug for allergic rhinitis.