Bronchodilators are probably the most commonly used medicines for asthma. They work by relaxing the muscles around the airways during an asthma attack.


There are many different bronchodilator medicines. Doctors usually group these medicines together by how they cause the muscles around the airways to relax.

The three most common groups are:

  • beta-agonists – albuterol (Proventil, Ventolin), salbutamol, metaproteronol (Alupent, Metaprel), and terbutaline (Brethine)
  • anticholinergics – ipratropium (Atrovent)
  • methylxanthines – theophylline (Theodur)

There are many ways to take beta-agonist medications:

  • inhaled using a metered dose inhaler
  • inhaled using a nebulizer
  • inhaled using a dry powder inhaler
  • swallowed as a liquid or tablet
  • taken as shots

For most people with asthma, inhaled medicines are the first choice because they begin to work very fast (usually in less than five minutes), and they don’t have too many side effects (the medicine goes right into the lungs and does not go to other parts of the body). Liquids or tablets don’t work as fast (30 minutes or more to start working), but they may keep working for as long as 4 to 6 hours. Shots are sometimes used in a doctor’s office or an emergency room for very bad asthma attacks. They work very fast (usually in less than five minutes), but last only about 20 minutes.

Inhaled beta-agonists are good at stopping mild asthma attacks and preventing attacks caused by exercise. Some people use these medicines every day (3-4 times a day) to keep their asthma under control.

Side Effects of Beta-Agonist Medicines

Sometimes asthma medicines make people feel weird or sick at the same time the medicine is making their asthma better. These feelings are called “side effects“.

Some of the side effects that people can get from beta-agonists are:

  • heart beating very fast
  • feeling very shaky or nervous
  • feeling scared or worried
  • feeling sick to your stomach (nauseous)

Most of the time, these side effects get better as your body gets used to the medicine. Sometimes, side effects are so bad that people can’t take the medicine any more. Some of these type of side effects are:

  • bad pain in the chest
  • your heart beating very fast or irregularly
  • feeling very dizzy
  • feeling very sick to your stomach (nausea) or vomiting

Call your doctor right away if you, or anybody you know, has any of these side effects.

Beta-agonist medicines may help people with asthma but they don’t make swelling in the airways go away. They also don’t prevent swelling in the airways. When people need to use beta-agonist medicines a lot, it may mean that the swelling in the airways is getting worse. If you need to use a beta-agonist medicine every day or if you use it more than 3-4 times in a single day, your asthma may be getting much worse. You may need another kind of medicine, and you should talk with your doctor right away.