Asthma is a chronic disease that affects the tubes that carry the air you breathe (and most importantly the oxygen) into your lungs. People who have asthma have airways that are very sensitive to common allergens (such as pollen, dust mites, and animal dander) and irritants (such as certain chemicals, tobacco or wood smoke, and cold air). Strenuous exercise, respiratory illness (such as the flu), certain drugs, and stress can also trigger asthma attacks.
Not surprisingly, most people who have asthma also have underlying allergies. But the two conditions are distinct, and many people who suffer from common allergies (hay fever) don’t have asthma. Allergies involve that mix of symptoms that includes nasal congestion, a runny nose, sneezing, itchy and watery eyes, and skin rashes. In contrast, asthma involves inflammation and narrowing of the airways in the lungs, and excessive mucus in the airways.
Specifically, during normal breathing, the bands of muscle surrounding your airways are relaxed. For people with asthma, exposures to allergens and irritants cause those muscles to spasm, constricting the airways and causing increased mucus production. Both of those factors make it more difficult for air to move in and out of the lungs. The resulting symptoms are wheezing (noisy breathing), coughing, shortness of breath, and a sensation of tightness in the chest. Those symptoms range from mild to severe and doctors often classify people with asthma according to the frequency and severity of their symptoms.
Table 1. Gradations of Asthma
|Mild Intermittent||Your asthma comes and goes, with symptoms either during the day or night, occurring twice a week or less. In between, you have no symptoms and your lung function is normal.|
|Mild Persistent||You have symptoms more than twice a week, but not every day. Symptoms at night usually occur more than twice a month and asthma attacks might affect your activity.|
|Moderate Persistent||You have symptoms every day and/or you have night symptoms more than once a week. The attacks often affect your activity.|
|Severe Persistent||You have symptoms throughout the day, most days. Symptoms often come at night as well. Activity is limited.|
Source: National Heart, Lung, and Blood Institute
The symptoms of chronic obstructive pulmonary disease can be very similar to those of asthma. But while asthma strikes children and adults and is to a large degree a result of your generic inheritance, COPD is caused by progressive damage to your lungs over many years. Smoking is far and away the most common cause (though COPD can be caused as well by exposure over time – usually in the workplace – to chemical fumes or organic dusts, or air pollution).
With chronic obstructive pulmonary (lung) disease, the airways and the sacs at the end of your airways lose their elasticity. There are two forms of COPD: emphysema and chronic bronchitis. With emphysema, the walls between the air sacs are eventually destroyed. In bronchitis, the airways are inflamed and swollen, often leading to recurrent infections and excessive sputum production. Many people with chronic obstructive pulmonary disease have both emphysema and chronic bronchitis.
Both asthma and COPD are quite common, and – as a result – the medicines we evaluate in this report are used by millions of people everyday. About 20 million Americans have asthma. Over five million are children. The disease usually first appears in childhood but adults can also develop it. Symptoms and frequency of attacks often decline as a person ages. But asthma can be dangerous at any age and time. Each year, about two million people visit a hospital emergency room because of an asthma attack, and about 4,500 die.
Table 2. Stages of COPD
|At Risk||Normal breathing test, but mild signs include chronic cough and sputum production.|
|Mild COPD||Mild airflow limitation on breathing test. Chronic cough and sputum production, but no awareness that breathing is limited.|
|Moderate COPD||Worsening airflow limitation on breathing test. Shortness of breath when working hard, walking fast, or during other brisk activities.|
|Severe COPD||Severe airflow limitation on breathing test. Shortness of breath after very little activity. Complications may include respiratory failure and heart failure.|
Source: National Heart, Lung, and Blood Institute
At least 12 million adults have chronic obstructive pulmonary (lung) disease. But it is widely under-diagnosed and experts believe that as many as 24 million people in the U.S. may have the condition. COPD directly causes or contributes to about 120,000 deaths per year, making it the fourth leading cause of death in the U.S.
Asthma and chronic obstructive pulmonary disease differ in one important respect. Although asthma is a chronic disease, it is highly manageable. With the right treatment, most people with asthma lead normal active lives and their lives are not shortened by their disease. In contrast, COPD is an irreversible disease that often gets worse over time. It shortens the lives of most people who have it, sometimes by many years. But that does not mean that it is not treatable and that people with chronic obstructive pulmonary (lung) disease – especially in the early stages – can not lead active, meaningful lives.
Six inhaled steroid medicines are available by prescription in the U.S. They are:
|Generic Name||Brand Name(s)||Available as a Generic Drug?|
Other medicines and approaches are used to treat both asthma and COPD. In particular, people with either condition may have to use so-called “quick relief inhalers. This is a class of medicines used primarily when a person is in the middle of an asthma or chronic obstructive pulmonary disease attack, when breathing is very difficult. The drugs act rapidly – within minutes – to open breathing passages, and provide relief for up to six hours. They are only used when you are having an attack, and not – like inhaled steroids – everyday to keep symptoms and attacks at bay and your airways open.
Among the quick-acting relievers (also called bronchodilators) are albuterol (Ventolin, Proventil), bitolterol (Tornalate), metaproterenol (Alupent), and pirbuterol (Maxair).
Two longer-acting non-steroid bronchodilators are also available. One is salmeterol (Serevent) and the other is formoterol (Foradil). Also, two other drugs combine these long-acting relievers with inhaled steroids. One is Advair (a combination of salmeterol and fluticasone) and the other is Symbicort (a combination of budesonide and formoterol). Symbicort is not yet available in the U.S.
Important safety and risk issues have been raised in the last several years about the long-acting bronchodilators. Some studies have linked them to a higher risk of death during asthma attacks, although a cause and effect relationship has not yet been confirmed. For this reason, the FDA in November 2005 issued an advisory saying that the long-acting bronchodilators and the combination drugs should only be used in people whose asthma is not adequately controlled by inhaled steroids alone.
Advair has been widely advertised to consumers. If your doctor has prescribed Advair, we would urge you to discuss with him or her the safety issues that have been raised about this medicine.
Some nonprescription quick-acting relievers are also available. Two common ones are Bronkaid and Primatene Mist. These drugs may be useful to some people with mild asthma but they should not be taken at all by people with diabetes, thyroid or heart disease, or high blood pressure. And they should not be used by people with COPD. If you are taking one of these over-the-counter medicines on a regular basis, you should talk with your doctor. They are not meant to be taken for a long period of time. And if you require that much help, it means your asthma or chronic obstructive pulmonary (lung) disease requires more serious medical attention.
One other inhaled medicine is sometimes used to treat asthma. It’s called cromolyn (Intal). A recent analysis of the scientific evidence found that inhaled steroids provided significantly better control of attacks and symptoms than cromolyn.
People with asthma or COPD may also take pills to help relieve their symptoms. For example, if you have asthma your doctor may prescribe a drug called montelukast (Singulair) or one called zafirlukast (Accolate). There’s pretty good evidence these drugs work, but they are not considered to be as effective as inhaled steroids at reducing the severity of symptoms or the frequency of asthma attacks (the exception may be in obese people).
If you have chronic obstructive pulmonary disease, you doctor may prescribe an older drug called theophylline (Theo-24, Uniphyl) or an oral steroid (such as prednisone, prednisolone or methylprednisolone.) The evidence supporting use of theophylline or steroid pills in people who have COPD is not particularly strong, but these medicines may help certain people.