People with asthma often have two inhalers: one for daily maintenance and another for rescue when symptoms arise. SMART involves using one inhaler for rescue and prevention instead of two.

Asthma is a lifelong condition that affects around 1 in 13 Americans.

While there is no cure for asthma, inhaled medications can control and manage symptoms.

A person with asthma often has one inhaler for daily preventive use and another containing quick-acting medication to treat sudden asthma symptoms. Many experts now recommend using a single inhaler for everyday use and quick relief. They refer to this approach as single maintenance and reliever therapy, or “SMART.”

This article discusses SMART for asthma, what it , when doctors prescribe it, and how to use it. It also discusses possible side effects and other treatments for asthma.

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Asthma management typically involves taking at least two types of medication, including controller medication for “maintenance” and quick-relief medication for “rescue.”

Maintenance inhalers

These inhalers keep the airway from swelling, narrowing, and producing mucus. They are typically inhaled corticosteroids (ICS), such as budesonide and fluticasone. People often take these medications daily to help prevent asthma symptoms and manage the condition over time. They are also called “controllers” because they prevent or control common asthma symptoms.

People can inhale steroid medications or take them orally in pill or liquid form. They keep working for 12–24 hours.

Learn more about inhaled steroids.

Rescue inhalers

These rescue drugs work quickly to relieve sudden asthma symptoms. A person usually only takes them as needed.

Bronchodilators relax the muscles that squeeze the airways. These can be short-acting or long-acting.

Long-acting beta-agonists (LABAs) are controller medications often used in combination with an ICS. They keep the airways open for 12–24 hours at a time. Short-acting beta-agonists (SABA) are quick-relief medications. SABAs keep the airways open for 4–6 hours.

Other bronchodilators include short-acting muscarinic antagonists, long-acting muscarinic antagonists, and theophylline.

Learn more about asthma from our content hub.

In December 2020, the National Heart, Lung, and Blood Institute (NHLBI) updated its guidelines on asthma management and recommended the use of single maintenance and reliever therapy (SMART) for some people with asthma.

SMART involves using one inhaler that combines controller and quick-relief medications. The therapy contains a combination of an ICS and a long-acting beta-agonist. The ICS medication reduces swelling and mucus formation in the lungs, while the LABA prevents the muscles around the airways from tightening and works immediately to open the airways.

The current guidelines only recommend the combination medication budesonide/formoterol (Symbicort) for SMART.


SMART is the preferred treatment for individuals ages 6 years and older with moderate to severe persistent asthma and for people with a history of asthma exacerbations.

People who are effectively managing their asthma and do not have side effects, have not experienced exacerbations, and have no risk factors for exacerbations do not need to shift to SMART.


A 2018 review of studies found that those taking SMART had fewer asthma attacks than those receiving conventional treatments for persistent asthma.

A 2021 review of studies also found that doctors prefer SMART as a treatment for reducing the risk of severe exacerbations in adults with moderate to severe asthma.


The Food and Drug Administration (FDA) recently approved a generic version of Symbicort that costs about half the price. The actual price a person will pay for either drug depends on their insurance plan, their location, and the pharmacy they use.

A 2021 study on the health and economic consequences of SMART found that it is more cost-effective than fixed combination and fixed-dose ICS.

When using SMART, a person can take the medication only as needed or for daily use, based on their age and the severity of their symptoms.

Children ages 6 years and older

A child with moderate to severe persistent asthma can take one or two inhalations of the drug daily if using it as a controller medication and as needed to treat sudden symptoms. The recommended daily maximum for this age group is eight puffs.

Children and adults 12 years and older

Individuals with moderate to severe asthma should take one or two inhalations twice daily if using it for maintenance and as needed to manage sudden symptoms. They can take up to 12 puffs in a day.

Refer to the Symbicort prescribing information for more details.

The FDA only approved the budesonide/formoterol combination for daily use in individuals ages 6 years and older, not in SMART regimens. Thus, when doctors prescribe SMART, they consider it off-label, and it may not be covered by insurance.

Common side effects associated with Symbicort include:

Read more about the side effects of Symbicort.

A person using SMART may experience side effects similar to those of separate inhalers for control and quick-relief drugs or combination inhalers.

Potential side effects from inhaled steroids include:

However, these side effects are less common in low dose inhaled corticosteroids. SMART may reduce the risk of side effects by lowering the dose of ICS a person receives.

Formoterol may cause the following side effects:

Aside from controller and rescue inhalers, there are other medications and treatments available for asthma:

  • Biologics: Doctors usually give these medications to people with moderate to severe asthma. Biologic drugs target a specific protein or cell in the immune system to prevent inflammation in the airways. They are usually given through infusion or injection.
  • Leukotriene modifiers, such as Montelukast: Leukotrienes are chemicals the body releases that cause symptoms like coughing, excess mucus, muscle tightness, and difficulty breathing. These are long-term control medications that block the effect of leukotrienes or stop the body from producing them.
  • Cromolyn sodium: This is a mast cell stabilizer that prevents mast cells from releasing histamines and leukotrienes.

Studies and reviews find SMART effective in managing moderate to severe asthma, reducing the frequency and severity of attacks, and improving a person’s quality of life.

The National Asthma Education and Prevention Program and the Global Initiative for Asthma recommend SMART as a treatment for people with moderate to severe asthma.

Asthma is a long-term condition, but people can control asthma symptoms with short- or long-acting medications.

Since 2020, SMART uses one inhaler combining controller and quick-relief medications. This combination reduces the potential side effects of receiving only one form of medication, such as inhaled steroids.

A person can work closely with a doctor who can create an individualized asthma treatment plan according to their age, asthma severity, and needs.