Asthma is an inflammatory disease of the lungs characterized by bronchospasms and airflow obstruction. Its symptoms include episodes of shortness of breath, coughing, wheezing and chest tightness, which may occur several times per day in severe cases. Asthma is likely caused by a combination of genetics and environmental factors such as air pollution, especially allergens. Other triggers for asthma include drugs and strenuous physical activities. Asthma has no cure, so treatment consists of managing its symptoms, typically by avoiding triggers and taking medication. Asthma medication may be classified into those that treat acute attacks and those that control symptoms over the long term. Extremely severe cases of asthma may require hospitalization to administer corticosteroids and magnesium sulfate intravenously.
Identifying and avoiding triggers is the most effective treatment for asthma. Allergens are the most common triggers, but forms of air pollution such as cigarette smoke can also cause acute attacks. Increasingly strict laws on smoking have reduced the number of people who need to be hospitalized for asthma attacks. Non-selective beta-blockers are also triggers for asthma. This class of medications is primarily used to manage abnormal heart rhythms, typically to protect the heart after an initial attack. Non-selective beta blockers are so named because they're antagonists for both B1 and B2 receptors. Exercise is generally beneficial for people with asthma, although it can also be a trigger. Yoga may be able to provide minor relief of symptoms in some cases.
Medications that provide quick relief from acute symptoms of asthma generally include short-acting beta2-adrenoceptor agonists (SABA). Salbutamol, often marketed as albuterol in the United States, is one of the most common treatments for acute symptoms. Asthma sufferers who symptoms are triggered by exercise often take albuterol before exercising. Anticholinergic medications like ipratropium bromide are bronchodilators that also provide short-term relief from moderate to severe asthma symptoms, typically in combination with SABA medication. Asthma patients who can't tolerate SABA may also take anticholinergic drugs by themselves, although they're less helpful for severe cases requiring hospital admission. Adrenergic agonists like epinephrine have an efficacy that's similar to SABAs, although they're less selective. However, adrenergic agonists are no longer recommended due to the high cardiac stimulation they cause. Fast-acting medications for asthma are comparatively inexpensive. For example, 25 vials of albuterol are typically available from pharmacies for about $10 with a coupon.
The most effective treatments for the long-term control of asthma are inhaled corticosteroids like beclomethasone, although oral forms may also be used for persistent symptoms. Inhaled formulations are typically self-administered at least once a day, depending on severity. Long-acting beta-adrenoceptor agonists (LABAs) like formoterol and salmeterol are also effective in controlling asthma symptoms in adults when combined with inhaled corticosteroids. The benefits of LABA are less clear in children due to the increased risk of severe side effects. Current evidence indicates that the combination of inhaled corticosteroids and LABAs may improve lung function in children with asthma, but not the severity of exacerbations. Children who take LABAs as part of their long-term treatment for asthma may also require more frequent hospitalization due to the severity of their symptoms. A 60-blister inhaler of salmeterol is available from most pharmacies for about $400 with a coupon.