Asthma is a chronic condition in which inflammation of the airway in the lungs produces significant breathing difficulties, including cough, respiratory distress and wheezing. Asthma attacks are triggered by several factors, including allergies, exercise, smoke, dust and respiratory infections. Asthma medicines aim to treat acute illness and prevent reoccurrence of the symptoms, according to the National Heart,
Lung and Blood Institute.
Bronchodilators
Bronchodilators work by relaxing the airway, trying to force them open. During an asthma attack, inflammation narrows the airways, impeding adequate air flow and oxygen exchange. Bronchodilators work on the smooth muscle cells surrounding the airway and try to relax them, causing dilation or opening of the airway. Bronchodilators are delivered via a nebulizer, a machine that turns the liquid medicine into an easily inhaled vapor; or in a metered dose inhaler. The most common bronchodilator is albuterol.
Steroids
Steroids work by reducing inflammation surrounding the airways. They are used both during an acute worsening of asthma symptoms and also as preventive medicine for asthma exacerbations. Steroids work by suppressing the body's immune response, which is exaggerated with asthma. During an acute attack, steroids are given either by mouth or as an intravenous medicine. For prevention, steroids are used in a nebulizer or inhaled dosing. Nasal steroids are also used if the patient has symptoms of nasal allergies that contribute to their asthma.
Allergy medicines
Allergies can be an inciting factor in acute asthma attacks, so allergy medicines can be useful in the prevention of asthma exacerbations. A hormone called histamine triggers the body's response to allergens like pollen and dust. Antihistamines are therefore used to moderate the body's allergic reaction. Over-the-counter antihistamines include diphenhydramine, more commonly known as Benadryl. Other medicines used to moderate seasonal allergies include mast cell stabilizers. As the name implies, these drugs prevent mast cells, the main cells involved in the allergic response, from secreting histamine by stabilizing their cell membranes.
Anticholinergics
Anticholinergic drugs work to decrease constriction of the airway during an asthma attack. They decrease the amount of mucous secreted during the inflammatory response to asthma. Increased mucous contributes to the respiratory distress by clogging the already narrowed airway, and inhaled anticholinergics work to reduce this reaction. Ipratropium, or atrovent, is the most commonly used anticholinergic drug during an asthma attack.
