Drug Treatment: Controllers And Relievers
Not that long ago, asthma sufferers relied on just a single class of drug, the bronchodilators, which open the airways. Today, because we understand that inflammation is at the root of asthma, additional drugs are used to control the inflammation that leads to asthma. You probably will use two types of medicine, one to control (prevent) your asthma and the other to make it easier to breathe when your asthma symptoms crop up.
In fact, the best way to think about asthma drugs is in terms of controllers and relievers. The controller is the drug that treats the inflammation that's at the root of your asthma, whereas the reliever is a temporary quick fix to relieve symptoms.
When inflammation is controlled, bronchospasm (airway spasm) is less likely to occur. Most controllers manage or prevent inflammation that can be present in the airways of people who have asthma. Other controllers don’t affect inflammation, but they work “around-the-clock” to keep the airway muscles relaxed, so that the airways are less vulnerable to having bronchospasm when an allergy trigger hits.
It is usually recommended that you take your controller or controllers every day, even when you aren't having symptoms. A mistake that some asthma sufferers make is to stop taking their controller when their breathing feels fine. That strategy can work well for people who have only seasonal symptoms. For people with year-round symptoms, stopping controller medicines can allow inflammation (and asthma symptoms) to return.
Types of controllers include the following:
- Corticosteroids — Corticosteroids are the most potent and effective anti-inflammatory drugs currently available. Usually, inhaled corticosteroids are used for long-term control of asthma. Oral corticosteroids (in pill form) provide a higher dose, and these can be used to regain control of asthma after several days of treatment during a significant flare-up. Oral corticosteroids are also used for long-term control when asthma is severe.
- Cromolyn sodium and nedocromil — These anti-inflammatory drugs may be the initial choice for long-term therapy in children. They also can be used preventively, before exercise or before unavoidable exposure to a trigger. These drugs are not always as effective as are corticosteroid inhalers, but they can be a good choice for some people with mild symptoms.
- Long-acting beta-2 agonists — These long-acting airway-opening drugs (bronchodilators) are used with anti-inflammatory drugs for long-term control of symptoms, especially nighttime symptoms. These drugs also may prevent exercise-induced asthma symptoms. Examples of long-acting airway opening medicines are salmeterol (Serevent), formoterol (Foradil), and the combination inhaler that pairs salmeterol with a corticosteroid (Advair). Doctors are cautious about their use of these long-acting airway openers because of a public health advisory warning that the US Food and Drug Administration issued in 2005. These drugs may put some people at risk for having more severe or even fatal asthma flares, even though they appear to reduce the frequency of flares for most people who use them. Because problems have been rare and because the medications provide valuable symptom relief for many people, lung specialists continue to recommend these medicines to many patients, although the drugs are used with more caution.
- Methylxanthines — Sustained-release theophylline is a bronchodilator. It may be used along with inhaled corticosteroids to prevent nighttime asthma symptoms. Methylxanthines such as theophylline are not often used in adults because of potential side effects that can stress the heart and because this drug can interact with some other commonly used medicines, leading to side effects.
- Leukotriene modifiers — Zafirlukast, zileuton or montelukast may be considered an alternative to low doses of inhaled corticosteroids for patients aged 12 years or older with mild persistent asthma. Montelukast has been studied in children as young as 1 year old, but it is not widely used in young children. Because corticosteroid inhalers are so effective for asthma control, most doctors do not select these alternative drugs as their first choice of controller.
- Immunotherapy — Allergy shots can be useful for some people who have allergic asthma, particularly if the asthma is triggered by pollens, grasses, or other airborne particles in the environment. Allergy shots change the way your immune system reacts to an allergy exposure, causing you to have fewer symptoms.
Omalizumab (Xolair) is a treatment that can block the effect of IgE antibodies, which are part of allergic reactions. This treatment was recently approved for moderate to severe allergic asthma when corticosteroids cannot control symptoms. It is an injectable form of treatment. It is fairly rarely used, due to its expense and inconvenience.
Relievers play a different role than controllers do—they cause a quick change in your breathing tubes that makes your breathing easier. When inflammation or irritation constricts the airways (air-carrying tubes) in the lungs, a reliever opens them. It does this by relaxing the muscles around the tubes. The effect is like turning coffee-stirring straws into round, open drinking straws.
Relievers are available as inhalers or as nebulized (mist) treatments. Types of relievers include the following:
- Short-acting beta-2 agonists — These drugs, such as albuterol and pirbuterol, are the therapy of choice to relieve acute asthma symptoms and prevent exercise-induced symptoms.
- Anticholinergics — Ipratropium bromine (Atrovent) may provide some added benefit to inhaled beta-2 agonists for severe asthma attacks. They also may be an alternative for people who cannot tolerate inhaled beta-2 agonists.