What are bronchodilators?
Bronchodilators relieve asthma symptoms by relaxing the muscle bands that tighten around the airways. This action rapidly opens the airways, letting more air come in and out of the lungs. As a result, breathing improves. Bronchodilators also help clear mucus from the lungs. As the airways open, the mucus moves more freely and can be coughed out more easily.
There are two forms of bronchodilators:
- Short-acting bronchodilators_ relieve or stop _asthma symptoms; you take these to stop an asthma attack.
- Long-acting bronchodilators help _control _asthma symptoms by keeping the airways open for 12 hours; this helps prevent asthma attacks.
There are two main types of bronchodilator medicines:
- Beta 2-agonists (short and long-acting forms)
Short-acting Beta 2-agonists inhaled medicines include:
- Albuterol (Proventil® HFA, Ventolin® HFA, ProAir®HFA, Accuneb®)
- Levalbuterol (Xoponex® HFA, Xoponex® nebulizer solution)
- Albuterol and ipratropium bromide combination (DuoNeb® solution, Combivent Respimat®)
Short-acting beta 2-agonists are called "reliever" or "rescue" medicines because they stop asthma symptoms very quickly by opening the airways. These are the best medications for treating sudden and severe or new asthma symptoms. They work within 15 to 20 minutes and last four to six hours. They are also the medicines to use 15 to 20 minutes before exercise to prevent exercise-induced asthma symptoms. If you need to use your short-acting beta 2-agonists more than twice per week, talk to your doctor. This is a sign of unstable asthma and your doctor may want to change the dose of the long-term control medicines you take.
Beta 2-agonists - Long-acting forms include:
- Salmeterol (Serevent®)
- Formoterol (Foradil®)
- Combination medications: salmeterol and fluticasone (Advair®); formoterol and budesonide (Symbicort®); formoterol and mometasone (Dulera®). These contain both the long-acting beta agonist and an inhaled corticosteroid.
Salmeterol and formoterol are the only inhaled long-acting beta 2-agonists available. They are used twice a day to maintain open airways for long-term control and they must be used with an inhaled corticosteroid for the treatment of asthma. They have also been shown to be helpful in treating exercise-induced asthma. They are available in dry powder inhaler (DPI) form.
Side effects of beta 2-agonists include:
- Nervous or shaky feeling
- Overexcitement or hyperactivity
- Increased heart rate
- Upset stomach (rare)
- Trouble sleeping (rare)
Albuterol also is available in pills or syrups. These medicines tend to have more side effects because they are in higher doses and are absorbed through the bloodstream to get to the lungs. Inhaled forms are preferred because they are deposited directly in the lungs and therefore have fewer side effects.
There are two anticholinergic bronchodilators currently available — ipratropium bromide (Atrovent® HFA), which is available as a metered dose inhaler and nebulizer solution, and tiotropium bromide (Spiriva®), which is a dry powder inhaler. Ipratropium is used four times per day. Tiotropium is used only once per day and lasts 24 hours. It should be used at the same time every day. These are not quick-relief medications but they can add to the bronchodilator effect for certain asthmatics with difficult-to-control symptoms.
Side effects are minor; dry throat is the most common. If the medicine gets in your eyes, it might cause blurred vision for a short period of time.
Theophylline is another type of bronchodilator that is used to control asthma. Brand names include Uniphyl®, Elixophyllin®, Theochron and Theo-24®. Theophylline is available as a pill or as an intravenous (through the vein) drug. It is long-acting and prevents asthma attacks. Theophylline may be used to treat difficult-to-control or severe asthma and must be taken daily. When taking theophylline, blood tests are needed to make sure you are receiving the right amount of medicine.
Side effects include:
- Nausea and/or vomiting
- Stomach ache
- Rapid or irregular heartbeat
- Muscle cramps
- Jittery or nervous feeling
These side effects might be a warning of too much medicine. Call your doctor if you have any of these side effects. Tell all your doctors if you take theophylline for asthma because certain medicines —such as antibiotics containing erythromycin, or seizure and ulcer medicine—can interfere with the way theophylline works. Also, viral illnesses and cigarette smoking can change how your body responds to theophylline.
It is important to remember that asthma is a chronic (meaning always there) disease of the airways. Treatment with the right medications leads to better asthma control. Always follow the medication plan you have been given. If your asthma medicines are not controlling your symptoms or if you have any other questions make sure you contact your doctor. Remember that although asthma cannot be cured, it can be controlled by working with your doctor to find the care plan that is best for you.