Bronchodilators - Treating Your Condition: Smoking Cessation

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Bronchodilators

Long used to treat asthma, bronchodilator medications have become the first-line treatment for people with COPD, whether they have mainly chronic bronchitis, emphysema, or both. Bronchodilators, which are usually inhaled but can also be taken in pill form, relax the muscles around the airways to keep the airways from constricting. Although airway constriction is less severe in people with COPD than in people with bronchial asthma, these drugs offer significant relief to many people with COPD. Chances are that your doctor will have you try using a bronchodilator for several weeks to see if it helps. Your doctor will probably redo your pulmonary function tests to look for improvement and will also ask if your symptoms have diminished. If not, a second bronchodilator may be added.

It's important to understand what bronchodilators can and can't do. They can make you feel better by easing your symptoms. Specifically, they may reduce the hyperinflation of your lungs and your shortness of breath. Some people also have more stamina for exercise once they begin taking bronchodilators. But despite their benefits, bronchodilators are balms rather than cures. Although they make it easier to breathe, they may or may not improve your lung function as measured on pulmonary function tests. They typically increase FEV1 by less than 10%, although some patients have better responses.

There are two types of bronchodilators most often prescribed for this condition: anticholinergic agents and beta-2 agonists. (Another type of bronchodilator, theophylline, is used less frequently.) Although all of these medications relax the airways, they differ in how they work, how fast they work, and what side effects they cause.

Anticholinergic agents. These drugs block acetylcholine, a nervous system chemical that has many effects, one of them being to stimulate muscle contraction. The anticholinergic agents used most often for COPD are ipratropium (Atrovent) and tiotropium (Spiriva). Both are inhaled medications (see "Using inhaled medicines," below), but ipratropium is short-acting, used four times a day, while tiotropium is long-acting, inhaled just once a day.

Using inhaled medicines Inhalers and nebulizers are devices used to deliver medications into the lungs. Inhalers are small canisters that enable you to inhale the medication in one or more controlled puffs of a powder or a spray. Nebulizers are machines that deliver a continuous fine mist of medicine through a mouthpiece or face mask as you breathe normally for several minutes. Most people with COPD use inhalers because they are simpler and less expensive than nebulizers. Nebulizers are used mainly by people with severe disease who have difficulty using inhalers. If you use two inhaled drugs, you may have a separate inhaler for each, or your doctor may give you a preparation that combines two drugs in a single inhaler. For example, the product Combivent contains both albuterol and ipratropium. There are two types of inhalers: metered dose and dry powder. The type of inhaler you choose will depend on which drugs you are taking and how easy the inhaler is for you to use. Your doctor will probably make some recommendations. If you have trouble using an inhaler, your doctor may recommend a nebulizer. Metered-dose inhalers release a controlled dose of a drug in the form of an aerosol spray when you press the top of the canister. You inhale the spray through a mouthpiece. This can be tricky; if you don't inhale at just the right moment, the aerosol spray stays in your mouth or the back of your throat and doesn't pass into your lower airways. To get around this problem, your doctor may recommend a spacer, a tube that attaches to the inhaler's mouthpiece and makes it easier to draw the spray into your lungs. It's particularly important to hold your breath for several seconds after inhaling to make sure that you keep the medication in your airways. If you are told to take more than one inhalation, each puff from the device should be with a separate inhalation. Dry-powder inhalers, also known by the brand name Turbuhaler, operate on a different principle. You inhale a fine powder, rather than a spray, when you inhale from the container. Dry-powder inhalers may be easier to use than metered-dose inhalers because you don't have to coordinate your breathing with the device — the powder is released automatically when you inhale. Nebulizers, which deliver the medicine through a face mask or mouthpiece, allow you to breathe normally while receiving the treatment. The device consists of a chamber containing the drug and a compressor pump. Operated either by electricity or by hand, the nebulizer sends air across the chamber that contains the medicine. The stream of air scatters the drug into a fine mist, which passes into the face mask or mouthpiece. Whether you use an inhaler or a nebulizer, it's important to make sure that most of the medicine enters your lungs. If you use these devices incorrectly, much of the medicine can be lost in the air or dispersed in your mouth. Your doctor or nurse should be able to teach you the right way to use your inhaled medicine. If you are having pulmonary rehabilitation, a therapist will probably follow up to make sure you are using the device properly. Two ways to take your medicine. The portable metered-dose inhaler is most commonly used for inhaled medications such as bronchodilators and corticosteroids. But for people at home or in the hospital who want to breathe at their own pace while taking medication, a nebulizer attached to a larger pumping machine is a good option. Metered-dose inhaler with spacer Nebulizer

Anticholinergics are considered a first choice for maintenance therapy because they are at least as effective as the beta-2 agonists for improving lung function in COPD patients, but cause fewer side effects. As with other medications, each person's response is individual and can't be predicted. The most common side effect of ipratropium and tiotropium is dryness in the back of the throat. If you don't respond to ipratropium or tiotropium alone, your doctor may recommend that you take it with a beta-2 agonist.

Beta-2 agonists. These drugs work like epinephrine (adrenaline), a hormone released in the body under stress to prime you for fight-or-flight by such actions as causing your heart to pump harder. In patients whose airways are constricted, the drugs may relax the muscles of the airway walls that are causing the constriction. Beta-2 agonists can be inhaled via either an inhaler or a nebulizer, or they can be taken in pill form. The inhaled forms work fastest and have the fewest side effects. For this reason, the pills are rarely used.

There are many beta-2 agonists. The short-acting versions last for three to six hours. They are used mainly for quick relief during a flare up. The most often used short-acting beta-2 agonist is albuterol (Proventil, Ventolin). Some other beta-2 agonists, such as salmeterol (Serevent) and formoterol (Foradil), work for more than 12 hours. The long-acting beta-2 agonists are used daily for ongoing maintenance therapy and should not be used on an as-needed basis to relieve symptoms. Besides keeping the airways open, the long-acting beta-2 agonists may have another benefit: inhibiting bacteria such as Haemophilus influenzae, a bacterium, from attaching to cells in the airways. In this way, these drugs may help prevent respiratory infections and, therefore, also prevent acute exacerbations of the lung condition.

Beta-2 agonists have more side effects than anticholinergics, including anxiety, restlessness, and headaches. When overused, they can cause a fast and irregular heartbeat, which may require treatment. Some people find that beta-2 agonists become less effective over a period of weeks to months, but most patients do not have this problem. In addition, because beta-2 agonists speed the heart rate, they should be used with caution in people with heart disease. They also may interact dangerously with some other medications, such as beta blockers, diuretics, and certain antidepressants (tricyclics and monoamine oxidase inhibitors). Before taking a beta-2 agonist, you should tell your doctor if you are taking any other medicines.

Last updated:	May 23, 2007