Asthma in Women, Asthma in Pregnancy (cont.)
The safest and most effective asthma treatment is inhaled medication, including corticosteroids
Salmeterol is a relatively new medication that is a longer-acting b-agonist. It is often used in people frequently needing b-agonists, in hopes of decreasing the need for short-acting rescue medications. It is also sometimes added to inhaled corticosteroids to improve asthma control or to reduce the dosage of these inhaled corticosteroids needed for asthma control. Some research has shown that asthma control in people already using steroid MDI's is improved moreso by addition of salmeterol than by raising the dose of the steroid MDI. Of course, this means using two inhalers instead of one inhaler. Salmeterol is sometimes used as a long-term medication to prevent exercise-induced asthma, but there is some research showing that its effectiveness when used for this specific reason may slightly decrease gradually with time.
Cromolyn is a medication that has been around for a long time. It is one of the safest medications of all available prescription medications, but it is not very potent. It is used sometimes as maintenance therapy to prevent acute asthma attacks, but it does not help during an acute attack.
C.Maintenance Therapy: Oral (by mouth) for Long-Term
Use of theophylline requires blood tests to determine blood levels of the medication as part of its safety monitoring. It also has potential side effects, including nausea, increased heart rate (experienced as palpitations), irritability, and insomnia, among others. These side effects are similar to those of caffeine. It also has potential for many drug interactions, meaning it can affect the use of other medicines used at the same time for other conditions, and vice-versa. Acute illnesses can also alter its metabolism (how the drug acts in the body and is eliminated from the body). For these reasons it is infrequently used in asthma treatment. Newer medications particularly inhalers like salmeterol are more effective and have less side effects.
A new class of maintenance medicines has emerged in the last several years. In fact, they were the first new treatment to be approved in 20 years for chronic asthma They are pills that act to reduce the production of, or the action of, chemicals that the body itself makes during an asthma attack. These chemicals called leukotrienes are produced by the inflamed airway, and narrow the airways. These medications are called anti-leukotrienes. Depending on the medication, they either stop the production of the trouble-making leukotrienes, or else block the harmful action of the leukotrienes. It is hoped that they can reduce the need for, or possibly the dose of, other asthma medications. These medications include zafirlukast, montelukast, and zileuton. These antileukotriene drugs directly block bronchoconstriction but are also anti-inflammatory, whereas corticosteroids are only anti-inflammatory. These medications have not been compared to each other, so it is not known if one has any clear advantage over the others. Most of the benefit of these drugs is seen within 2-4 weeks of starting the medication (A), and they generally reduce the need for rescue therapy by 1/3rd (A). They help decrease nighttime asthma symptoms as well (A).
When compared head-to-head, the anti-leukotrienes and the inhaled steroids each help certain lung function tests, quality of life, night-time awakenings, numbers of asthma-control days, and asthma attacks. The two medications were each helpful as controller medications for chronic asthma. Both drugs were very well tolerated in terms of side effects. Other research has added anti-leukotrienes to high doses of inhaled steroids in chronic asthma patients. Patients who did have the anti-leukotriene added had a better chance of successfully reducing the inhaled steroid dose than those who did not add an anti-leukotriene to their inhaled corticosteroids. The anti-leukotrienes are not yet felt to be useful in severe asthma, and many people with milder asthma are already controlled and happy on either intermittent rescue medication or chronic inhaled corticosteroid MDI's with only occasional need for rescue medication.
It might be that these medications if used regularly for many weeks, are good at preventing exercise-induced asthma, as is being shown in recent research, and that they may help a certain type of asthma called aspirin-sensitive asthma. However, there are many issues that have come up regarding these medications; people may find using MDI's more convenient that taking these pills, MDI's in low doses have minimal absorption compared to pills thus possibly less potential for side effects, and long-term studies of these pills are not available yet. Also, zileuton has potential to cause abnormal liver function test in the blood, so that all people taking this medication will need liver test monitoring via blood tests at intervals, especially in the first 3 months of use. Therefore their precise role is still being determined, especially in the long-term. Specifically, we need long-term safety and effectiveness data, and need to clearly establish what specific group of asthmatics will benefit most from them. Probably for the time being, in real daily practice while we await research, their use is considered in the following mild to moderate asthmatics: those with less than optimal benefit from inhaled steroid, those with aspirin-sensitive asthma, and those needing high doses of inhaled or oral steroids.