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How Do Asthma Medicines Work?

Medically reviewed by: Nemours Medical Experts

Kids with asthma have what is called a chronic (say: KRAH-nik) health problem. This means that it's a problem that's always there. In asthma, the airways are always a little inflamed (irritated and swollen), even when a kid has no symptoms.

Everyday stuff such as exercise, pets, or cigarette smoke can make asthma symptoms worse (this is called an asthma flare-up). 

Luckily, medicine can help.

How Do Asthma Medicines Work?

Asthma medicines work in two ways:

  • Some medicines work right away to relax the muscles around the airways and open them, providing quick relief of symptoms. That's why they're often called quick-relief"fast-acting," or "rescue" medicines. They are usually inhaled (breathed in) using an inhaler device or a nebulizer. The most commonly used medicines for the quick relief of symptoms are called bronchodilators (such as albuterol).
  • Other medicines work over time to ease inflammation, which reduces swelling of the airways and limits mucus production. This can help to prevent symptoms. These are often called long-term control, "controller," or "maintenance" medicines. A kid usually needs to be take these every day, even when they feel fine and have no symptoms.

    Some kids with mild asthma might use anti-inflammatory medicines only when they have more symptoms instead of every day. These are also usually inhaled, but some types are swallowed as a pill or liquid. Different medicines can ease inflammation, but inhaled corticosteroids are used the most. These are not like the steroids some athletes use, and are a safe way to treat asthma.

Some kids will get both types of medicines from one inhaler device. They might need to use this “combination” inhaler every day to prevent symptoms, with added doses from it when they have symptoms. Some older kids with mild asthma might use a combination inhaler only for quick relief when they have symptoms, or before they exercise. Your health care team will help you figure out which inhaler is best for you, and show you how and when to use it.

For a more severe flare-up, some kids might need to take steroid pills or liquid for 5–7 days. These work fast to reduce inflammation when inhaled medicines aren’t quite enough. If a kid has a severe flare-up that needs treatment in the ER, they might get medicines by injection.

What Else Should I Know?

When you get asthma medicines through an inhaler, it's important to use a spacer, which helps get as much medicine as possible into your airways.

Always keep the medicine you use for quick symptom relief with you — at home, at school, on the basketball court, at the mall, and even on vacation.

If you have asthma, your doctor will decide which type of medicine you need and how often to take it. For many kids, that will change as they grow and their symptoms change.

Medically reviewed by: Nemours Medical Experts
Date reviewed: September 2023