Marc J. Sicklick, M.D., FAAAAI, FACAAI
Bronchodilators are medications used to relieve breathing problems such as shortness of breath or wheezing, and the sensation of chest tightness. They are often prescribed for people suffering from asthma, chronic obstructive pulmonary disease (COPD), emphysema or other lung conditions.
They come in several forms, including pills, liquids, as an injection or in an inhaler. Some forms are only available by prescription while others are available over-the-counter. Bronchodilators are often categorized as either “rescue” or “control” medications. Rescue (also called short-acting) medications provide immediate relief and are taken only to relieve symptoms. Control (or long-acting) medications are taken regularly to prevent symptoms from occurring. There are three main types of bronchodilators:
- Beta2 agonists (short- and long-acting)
- Theophylline (long-acting)
- Anticholinergics (long-acting)
Some potential side effects may result, and, as with all medications, patients are advised to consult with their physician before use.
Bronchodilators are medications taken to improve breathing. They help expand the airways and improve the breathing capacity of patients with bronchial asthma, chronic obstructive pulmonary disease (COPD), emphysema, pneumonia, bronchitis and other lung diseases. They may also be used to treat breathing-related symptoms associated with an allergic reaction.
Bronchodilators also help clean mucus from the lungs to improve breathing. As air passageways are opened, mucus moves more freely because it becomes thin and can be coughed out more easily.
Bronchodilators are sometimes called either “rescue” or “control” medications. Rescue medications are usually short-acting and are used for quick relief from symptoms. They work by relaxing the bands of muscle surrounding the airways. Control medications are long-acting medications taken daily to prevent breathing difficulties from occurring and to prevent long-term damage to the airways. Patients continue to take these medications even when symptoms do not occur.
It is vital to understand and follow all directions for taking bronchodilators, because patients often do not take their medication properly. For instance, many patients stop taking long-acting bronchodilators, which are preventive medications, when symptoms disappear. Long-acting bronchodilators are generally prescribed to be taken daily to be effective. They prevent inflammation and usually do not work to break an acute attack.
Short-acting bronchodilators, on the other hand, are prescribed only for occasional relief of symptoms. Patients who frequently use their inhalers may need to have their treatment regimen altered to include a long-acting bronchodilator.
For instance, an individual who must use a short-acting beta2 agonist more than twice a week to control intermittent asthma may need to begin long-term control therapy, according to the U.S. National Asthma Education and Prevention Program.
Bronchodilators are sometimes used in combination with other drugs to achieve maximum results. For example, an asthma patient might be prescribed an inhaled corticosteroid to control inflammation in conjunction with a long–acting bronchodilator, taken by inhaler, to open narrowed passageways, especially during the night.
Some bronchodilators are available over-the-counter, while others require a prescription. They come in oral (e.g., tablets, capsules, liquids), injected and inhaled forms.
Oral forms of bronchodilators tend to have more side effects because they are delivered in higher doses and absorbed into the bloodstream. Inhaled bronchodilators are directly deposited in the lungs and tend to cause fewer side effects.
Bronchodilators can be inhaled directly into the lungs using the following devices:
- Inhalers. Used primarily to treat asthma, chronic obstructive pulmonary disease (COPD) and other respiratory problems. Inhalers release small amounts of the required drug when breathed in. They can be used to prevent symptoms from occurring or to relieve symptoms.
One of the most common types of drug/inhaler combinations (albuterol in a metered-dose inhaler), is currently being phased out of the United States market due to environmental concerns. The Food and Drug Administration (FDA) has requested that these inhalers be removed from the market by 2009. A new type of inhaler, known as the hydrofluoroalkane-based (HFA) inhaler, offers the same albuterol in a different delivery vehicle (one that does not damage the environment). This will not lead to any significant change as far as the patient is concerned.
- Insufflation cartridges. Provide a greater dose than inhalers.
- Nebulizers. These devices deliver the largest dose and provide the fastest relief. A face mask or a mouthpiece provides a mixture of compressed air and the specific drug.
Types and differences of bronchodilators
Some common bronchodilator medications include:
|Generic Name||Brand Name(s)|
|albuterol||Accuneb, Proventil, Ventolin, Volmax|
|epinephrine||Adrenalin, ANA-Guard, AsthmaHaler, Bronitin Mist, Bronkaid Mist, Epi-Pen, Epifrin, Epinal, Eppy, Glaucon, Medihaler-Epi, Primatene Mist, Sus-Phrine|
|isoetharine||Bisorine, Bronkosol, Bronkometer|
|isoproterenol||Aerolone, Isuprel, Medihaler-Iso, Norisodrine Aerotrol, Vapo-Iso|
|terbutaline||Brethaire, Brethine, Bricanyl|
|theophylline||Elixophyllin, Slo-Bid, Theo-Dur, Theo-24, Uniphyl|
There are three types of bronchodilators:
- Beta2 agonists (short- and long-acting). These drugs relax the bronchial muscles to prevent narrowing and to open the airways. Short-acting beta2 agonists are most commonly used to relieve a sudden asthma attack or to prevent an attack while or after exercising.
The short-acting beta2 agonists are inhaled medications that give quick “rescue” and offer temporary relief from asthma symptoms or flare-ups. Long-acting beta2 agonists take longer to begin working but usually relieve airway constriction for up to 12 hours. Long-acting beta2 agonists are prescribed for use with other drugs, such as inhaled steroids. The most commonly used beta2 agonists include albuterol, bitolterol, pirbuterol, metoproterenol, terbutaline and salmeterol. They can be taken orally or inhaled.
- Theophylline (long-acting). A type of methylxanthine. This type of bronchodilator works by relaxing the lung muscles and making the airway passages more resistant to irritants. Chemically related to caffeine, it is long–acting and prevents asthma attacks but must be taken daily. Theophylline has been reported to cause side effects such as nervousness, nausea, heart palpitations and seizures. Therefore, it is not the first choice and usually used only for symptoms that do not respond to other bronchodilators.
- Anticholinergics (long–acting). Medications that smooth muscle contractions and reduce excess mucus in the bronchi (the tubes that transport air to and from the lungs). This causes the breathing passages to widen and relax, making it easier to breathe. Anticholinergics may take 1 to 3 hours to work and are therefore not rescue or quick-relief drugs. They are rarely used as the only medication in the treatment of breathing problems. Anticholinergics are most useful when used in conjunction with other bronchodilators to prolong their effects. Some types seem to work more effectively in improving airflow in patients with chronic obstructive pulmonary disease (COPD) rather than with asthma sufferers. They are available in inhalant form.
Conditions treated with bronchodilators
Bronchodilators are prescribed for a variety of conditions, including:
- Asthma. A condition in which airway passages become blocked or obstructed causing shortness of breath. Bronchodilators open the airways by relaxing the smooth muscles in these airways. They are among the most commonly used medications for asthma.
- Chronic bronchitis. Inflammation of the bronchial tube linings that lead to a persistent cough. Short-acting bronchodilators relieve coughing and shortness of breath.
- Chronic obstructive pulmonary disease (COPD). A progressive lung disease that decreases the ability of the lungs to perform ventilation. Bronchodilators smooth muscle constriction in the airways, increasing the flow of air.
- Mucus in the lungs. A build-up of mucus in the lungs causes a constriction of breathing passages and can lead to coughing. Bronchodilators work to diminish and thin mucus production.
- Emphysema. A condition in which the normal exchange of oxygen and carbon dioxide in the lungs is impaired due to damaged or collapsed air sacs. Bronchodilators improve air flow.
- Exercise-induced asthma (EIA). A temporary narrowing of the airways caused by excessive exercise that produces asthma-like symptoms. Bronchodilators administered before and after exercise keep the bronchial air passages open and prevent symptoms associated with this condition.
- Wheezing. A whistling sound caused by the friction of air going through narrowed airways. Bronchodilators widen the narrow passageways and relax the small tubes in the lungs, making breathing easier.
Conditions of concern with bronchodilators
Patients should not take bronchodilators, unless prescribed by a physician, if they have been diagnosed with any of the following conditions:
- Heart or blood vessel disease. Bronchodilators may worsen these conditions.
- High blood pressure. Some types of bronchodilators may elevate blood pressure.
- Arrhythmias (abnormal heart rhythms). Some type of bronchodilators may worsen these conditions.
- Hyperthyroidism (overactive thyroid). Chances of bronchodilator side effects may be increased.
- Pheochromocytoma (a rare and usually benign cell tumor that produces adrenaline, raising blood pressure and heart rate). Bronchodilators may raise blood pressure and heart rate.
- Urinary problems. Bronchodilators may not be recommended for people with urinary problems because they may reduce urine output.
- Glaucoma. Bronchodilators may not be recommended for people with glaucoma.
- Viral illnesses. These conditions can alter the way a person’s body responds to certain bronchodilators.
- Pregnancy. Some studies have shown birth defects in animals when given large doses of bronchodilators. Patients are advised to consult their physician.
Potential side effects of bronchodilators
The form and severity of side effects will vary depending on the type of bronchodilator. High doses of short-acting beta2 agonists, for instance, have been associated with hypokalemia (low potassium levels in the blood, which can result in weakness) and abnormal heart rhythms.
A large clinical study found that the long-acting salmeterol drug was associated with a small, but statistically significant number of deaths in asthma patients. After investigating the drug, the Food and Drug Administration (FDA) updated the safety warnings on all long-acting beta2 agonists (LABA). The labels recommend that LABA medications not be the first medication used to treat asthma and that they should only be used as an additional therapy when a patient’s symptoms fail to respond to other asthma medications, such as low-to-medium dose inhaled corticosteroids.
Patients concerned about these warnings should NOT stop taking prescribed medication without first consulting their physician. The risk of untreated asthma is much higher than the risk of death from salmeterol.
Regular, frequent use of certain bronchodilators by a person with asthma may even worsen the condition. Patients taking bronchodilators are advised to call their physicians immediately if they experience any of the following symptoms:
- Chest pain
- Severe headache
- Severe vomiting
- Fever or chills
- Fast or pounding heartbeat
- Skin rash
- Choking or difficulty swallowing
- Loud or high-pitched breathing
- Worsening of symptoms
- Swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
Less serious side effects should be brought to the attention of a physician and may include:
- Anxiety, nervousness, agitation or hyperactivity
- Muscle cramps or tremors
- Dizziness or light-headedness
- Dryness or irritation of mouth or throat
- Unpleasant taste
- Nausea, stomachache or vomiting
- Pinkish-red saliva (isoproterenol only)
- Elevated blood pressure
- Difficulty urinating
- Tingling of the hands and feet
- Arching of the back
Patients should discuss all side effects with their physician because certain side effects indicate that the person is receiving too much medication. Physicians may conduct blood tests to determine if the patient is receiving the proper amount.
In addition, certain bronchodilators may cause temporary blurred vision if the medication comes into direct contact with the eyes.
Drug and other interactions
Patients should consult their physicians before taking any additional prescriptions, over-the-counter medications, nutritional supplements or herbal medications. Of particular concern to individuals taking bronchodilators are:
- Antihypertensives (medications to treat high blood pressure). Bronchodilator use may lessen the effectiveness of these drugs.
- Anti-arrhythmics (medications to treat abnormal heart beats). Bronchodilators used in conjunction with these drugs may lessen their effectiveness.
- Antibiotics (medications to treat bacterial infection). These medications may interfere with the function of bronchodilators.
- Antiseizure medications. Bronchodilator use may lessen the effectiveness of these drugs.
- Ulcer medications. These medications may interfere with the function of bronchodilators.
- Psychiatric medications. Use of some bronchodilators in conjunction with certain medications used to treat psychiatric disorders may lead to a potentially dangerous drop in blood pressure and/or rapid heartbeat.
- Smoke. Smoking or exposure to second-hand smoke can interfere with the way the body responds to certain bronchodilators.
- Caffeine. Coffee, tea, colas and other caffeinated drinks can change the effectiveness of certain bronchodilators.
Symptoms of bronchodilator overdose
Symptoms of overdose can be similar to the medication’s side effects, but are usually more severe. Patients exhibiting any of these symptoms should contact their physicians immediately:
- Problems breathing
- Blue lips and fingernails
- Continued blurred vision, dilated pupils
- Low blood pressure
- Chest pain
- Severe headache
- Vomiting and nausea
- Rapid heartbeat
For less severe symptoms that do not indicate overdose but require contacting a physician, see Potential side effects.
Elderly use issues with bronchodilators
The medicine salmeterol has been tested in a limited number of patients 65 years of age or older and has not been shown to cause different side effects or problems in older people than it does in younger adults.
The medicines albuterol, bitolterol, epinephrine, fenoterol, isoetharine, isoproterenol, metaproterenol, pirbuterol, procaterol, and terbutaline have not been studied specifically in older adults. It is not known whether or not they work exactly the same way as they do in younger adults or if they cause different side effects among the older adult population.
Lifestyle considerations with bronchodilators
Patients or caregivers of patients using bronchodilators need to know how to monitor and measure responses to these medications. The correct use and maintenance of devices such as nebulizers, peak flow meters and inhalers are very important.
Teenagers sometimes perceive a stigma associated with inhaler therapy because it can make them feel different, not well or not part of the group. Parents may wish to point out that many athletes with asthma use bronchodilators and such people are proof that it is still possible to participate and excel in physical activities. People any age taking bronchodilators are encouraged to discuss their concerns and activity levels with their physicians.
Some adolescents may deny having asthma or other breathing disorders that require bronchodilators and discontinue taking their medications. Caregivers need to be aware of this issue and monitor medication use until the adolescent is ready to manage his or her own care. Because bronchodilators are basically rescue medications, users need to have their medications with them at all times.
Pregnancy use issues with bronchodilators
Certain bronchodilators are used to treat asthma in pregnant women, including albuterol, bitolterol, formoterol, metaproterenol and salmeterol. Although there have been no studies on birth defects in humans, and no reported cases definitively linking birth defects to bronchodilators, some animal studies involving bronchodilators report birth defects when given in doses many times higher than human doses.
Pregnant women who were given epinephrine under the skin have had more birth defects than expected in some studies, although the severity of the mother’s asthma may have contributed to this result.
The medicines fenoterol, isoproterenol, pirbuterol, procaterol and terbutaline have not been shown to cause birth defects in animal studies. Women taking bronchodilators who are pregnant or wish to become pregnant are encouraged to discuss potential benefits and risks with their physician.
It is not known at this time whether bronchodilators pass into the breast milk. Although most medicines pass into breast milk in small amounts, many of them are considered safe for nursing infants. Mothers who use bronchodilators and who wish to breastfeed are encouraged to discuss this with their physician.
Child use issues with bronchodilators
Generally, bronchodilators are used on an as–needed basis when there is difficulty breathing or a child is having trouble with coughing or wheezing.
Studies performed to date have not demonstrated specific problems that would limit the usefulness of bronchodilators in children. However, isoetharine is not recommended for their use. Bronchodilators routinely prescribed for children include albuterol, bitolterol, levalbuterol, proventil, pirbuterol, terbutaline, levalbuterol.
Questions for your doctor
Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions regarding bronchodilators:
- Why are you recommending that I use a bronchodilator?
- How long will I need to use the drug?
- How often will I need to use the drug?
- Does this drug pose any risk to me?
- What side effects may I develop while taking this drug?
- Are there any side effects I should immediately report to you?
- Can this drug interact with any of my other medications?
- How will I know if the drug is working?
- Is it possible for me overdose on this drug? How will I know if I have taken too much?
- Under what circumstances will you take me off this drug?
- Should I reduce my consumption of caffeine while on this drug?