Checkup on Health: Take control of your asthma
by Sam Louie, M.D.
Every asthma sufferer knows it's spring, and ‘tis the season to be wheezing. One in every five Americans has bronchial asthma: incidence in both children and adults has increased over the past 25 years. The disease is particularly prevalent in California's Central Valley, where our warm spring air holds a high concentration of pollens, a common trigger for asthma attacks.
Asthma is caused by several mechanisms, all of which cause the airways to work less effectively. The first mechanism is a spasm or contraction of the muscles surrounding the tubes (bronchi) that bring air into the lungs. This "bronchospasm" causes the air passages to narrow, making airflow more difficult. Secondly, the lining of the bronchi and other air passages become swollen and irritated, further restricting airflow. To add insult to injury, mucus is produced, clogging the already narrowed airways to an even greater degree.
Not surprisingly, an asthma attack makes a person feel a need to fight for each breath. Attacks almost always involve rapid breathing, wheezing (a breathy whistle or accordion-like noise), coughing, chest tightness, and a relatively long expiration with each breath. Some people do not have the characteristic wheezing, but instead have a persistent cough as their only symptom.
Asthma usually worsens at night. This is believed to be due to our body's natural variation throughout the day, known as our circadian rhythm. Hormones we make that help asthma, such as cortisol and epinephrine, are low during nighttime hours, causing bronchial inflammation to increase.
Most asthma sufferers are aware of circumstances that bring on their attacks. Many are affected by strenuous exercise or cold air, or typical allergens such as perfumes, aspirin, animals (especially cats), or foods such as nuts or eggs. Some environmental triggers — like dust mites and pollens — may be so pervasive that they are unknown or difficult to avoid. Many people can control their asthma well until they get sick with something else, such as a cold or flu.
Medications for asthma treatment
Because the physiology of asthma is multifactorial and the triggers that set it off vary between individuals, treatment must be carefully tailored to each patient's needs. Drug treatment can be divided into "rescue" and "control" categories; some are best once symptoms have started and others are better for good overall control and attack prevention.
The most effective rescue drugs are short-acting bronchodilators, such as albuterol and metaproterenol. These inhaled aerosols relax the smooth muscle around the airways, allowing them to open. They should be used on an as-needed basis for mild, chronic asthma and during asthma attacks.
The most effective control drugs are inhaled corticosteroids, which are used for moderate to severe asthma. Many are available; the newer drugs promise only twice-a-day dosing. A new long-acting bronchodilator, salmeterol (Serevent®), is in the form of an inhalable dry powder, and has been found to enhance the benefits achieved with inhaled corticosteroids. Corticosteroids that are also in a dry powder form, such as Flovent® and Pulmicort®, are also newly available.
A new line of asthma defense acts by blocking the action of certain lipids or fats — called leukotrienes — that promote the inflammatory response. Singulair® is one such drug that was recently approved for both adults and children as young as six. It has the advantage of being taken only once a day and is available as a chewable tablet.
I encourage my patients to learn as much as they can and to demand good control over this disease. An asthma patient can expect to get a good night's sleep and wake up refreshed with good energy. The key is balancing a healthy lifestyle, regular exercise and the proper use of medications.
Children with asthma
Children with asthma should learn as early as they are able to self-administer their medications. They should participate in sports and other activities, using medications as necessary. Many find that sports which involve short bursts of activity, such as gymnastics or baseball, are easier to tolerate than those like basketball or long-distance running that require a more sustained aerobic level.