The Actions of Bronchodilators

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What is a Bronchodilator?

A bronchodilator is a drug that opens up the air passages in the lungs. There are three classes of bronchodilators: beta-agonist, anticholinergics, and theophylline. All three relax the muscles in the lungs. Some beta-agonists also reduce the amount of mucus in the airways, and theophylline also acts to prevent swelling of the airways.

Relieving Asthma Attacks With Bronchodilators

The sudden onset of asthma constricts the air passages in the lungs, which makes it difficult to breathe. The actions of bronchodilators relieve the symptoms by relaxing the smooth muscles in the bronchi and bronchioles. It only takes a few minutes for the drug to take effect, and the relief lasts for a few hours. Bronchodilators that work immediately and last for a short period of time are called short-acting bronchodilators. This type of drug is also used to prevent exercise-induced asthma. Typically, the drug is taken 15 minutes before exercising.

Types of Short-Acting Bronchodilators

There are several short-acting bronchodilators that treat asthma attacks. Albuterol is a beta-agonist that is dispensed through an inhaler. It is used to relieve wheezing and shortness of breath. Alupent is a beta-agonist that is available as a syrup or aerosol. Both of these drugs have potential side effects including headaches, nervousness, and rapid heart beat.

Combivent and DuoNeb are combination drugs that contain a beta-agonist and an anticholinergic. Both drugs combine albuterol and ipratropium to treat coughing associated with chronic obstructive pulmonary disease. Possible side effects include coughing, dizziness, and dry mouth.

Preventing Future Asthma Attacks

A second type of bronchodilators, termed long-acting bronchodilators, control asthma over a long period of time. Typically, the actions of these bronchodilators take effect between 15 and 45 minutes and last 12 hours or more. These drugs relax the smooth muscles of the bronchial tubes and prevent inflammation. The combined effect prevents the onset of asthma symptoms.

Types of Long-Acting Bronchodilators

Long-acting bronchodilators contain two drugs. One is a bronchodilator, which relaxes the smooth muscles of the airways, and the second drug is a steroid, which reduces inflammation. Advair is a long-acting bronchodilator that consists of fluticasone and albuterol. It prevents asthma attacks and flare-ups of chronic obstructive pulmonary disease. Side effects of advair include chest tightness, dizziness, and fast heart beats.

Symbicort is another long-acting bronchodilator. It contains budesonide and formoterol. Budesonide is the steroid and Formoterol is the bronchodilator. The drug is used to prevent symptoms of asthma and COPD. Side effects include the worsening of asthma symptoms, headaches, and chest pains.

There is a significant risk of death when taking long-acting bronchodilators. It is important to follow the recommended dosages and directions given by a doctor.


1. “Bronchodilators and Asthma.” WebMD.

2. “Asthma and Bronchodilators.” Partners Asthma Center.

3. “Bronchodilator Medicines - How They Work.” NHS.

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