Controller Medications

Having asthma means having long-term inflammation (swelling) in your airways. Controller medications are used to treat this underyling inflammation to greatly reduce asthma symptoms and help prevent asthma attacks. Your healthcare professional will probably prescribe a controller as part of your long-term treatment plan of asthma. If you have had asthma for some time and it is poorly controlled, your doctor will probably want to add a controller medication if you aren’t already using one.

When you start taking controller medications, you may not notice a difference right away. It may take a few weeks before the inflammation in your airways is reduced. Even if you do not feel better right away, do not stop taking your controller medication unless your doctor tells you to.

Remember, controllers do not immediately relieve wheezing, coughing or chest tightness, and should not be used to treat a severe asthma attack. Make sure you understand the difference between your reliever medication, which provides quick relief during an asthma episode, and your controller medication, which controls your underlying inflammation so that you’re less likely to experience these symptoms in the first place.

Is Your Asthma Well Controlled?

If your asthma is poorly controlled your healthcare professional will probably put you on a controller medication. You have good asthma control if you:

  • Do not have any breathing difficulties, cough or wheeze most days
  • Sleep through the night without wakening with cough, wheeze or chest tightness
  • Can exercise without cough, wheeze or chest tightness
  • Do not miss work or school because of asthma
  • Have a normal  breathing (spirometry) test
  • Do not need your reliever inhaler 2 or more times a week (except for use with exercise)

You can check to see if you are over-relying on your reliever (rescue) inhaler by taking this quiz: Rate Your Reliance

Controllers: Inhaled Corticosteroids

Inhaled corticosteroids are a type of medication that are very effective at reducing inflammation in the airway. Corticosteroids are the mainstay of what is called “controller” or “preventer” treatment in asthma. For most people with asthma, a controller corticosteroid will be taken as a puffer (or inhaler). This delivers the medication to the lungs, right to where it is needed.

Most people with asthma achieve good control with a corticosteroid inhaler. Inability to achieve good control with a corticosteroid inhaler should raise a red flag, and your asthma should be reassessed.

Who should take an inhaled corticosteroid?

Everyone with asthma, even mild asthma, benefits from regular use of inhaled corticosteroids. When used regularly, inhaled corticosteroids reduce inflammation and mucous in the airways, making the lungs less sensitive to triggers. They are also the best defence against possible long-term lung damage and airway remodelling.

What do I need to know about inhaled corticosteroids?

It can take weeks for an inhaled corticosteroid to reduce the inflammation in your airways, so be patient. The longer you are using it, the less you will need to use your reliever medication, since your asthma will be better controlled.

Inhaled corticosteroids are not for the relief of sudden-onset asthma symptoms.When you are feeling better, do not stop taking the inhaled corticosteroid. Instead, talk to your healthcare provider about adjusting the dose. The inhaled corticosteroid is keeping your asthma under control. If you stop taking it, the inflammation and your symptoms will return.

Will inhaled corticosteroids used to treat asthma cause dangerous side effects?

The corticosteroids that are inhaled to treat asthma today are considered safe. This is because the medicine, which is breathed in through a puffer, goes directly into the lungs where it reduces inflammation in the airways. A steroid tablet (oral corticosteroids) that is swallowed has more side effects because a large amount goes into the blood stream and is carried to other parts of the body.

Side effects from inhaled corticosteroids are minor when the proper amount is taken. The common side effects of inhaled corticosteroids are hoarse voice, sore throat, and a mild throat infection called thrush (yeast infection). Sore throat and thrush are commonly caused by poor puffer technique. Show your healthcare provider how you use your puffer. You may need a spacer if you are using a type of puffer known as a metered dose inhaler (MDI). Rinsing out your mouth with water after every dose of inhaled corticosteroids will also help reduce these side effects.

What is the difference between anabolic and inhaled corticosteroids?

There are a number of misconceptions about inhaled corticosteroids. For example, some people mistakenly believe that they are the same as the anabolic steroids that are sometimes abused by athletes.

Corticosteroids and anabolic steroids are two completely different medications. The term “steroid” in both names just means that one piece of their chemical structure is similar. The other parts of the two molecules are different from each other, so their effects on the body are also very different.

Anabolic steroids are variations of the male hormone testosterone. On the other hand, the steroids used in asthma are corticosteroids, which are closely related to hormones that your body naturally produces to fight inflammation in the various tissues of the body. Corticosteroids do not produce the same kinds of side effects as anabolic steroids. With inhaled corticosteroids, you are taking a very small dose of the medication that goes exactly to where it is needed in your lungs, so the risk of it producing side effects elsewhere in your body is very low or none at all.

Corticosteroids are the steroids used to treat asthma. Corticosteroids do not build muscle or enhance performance. Corticosteroids are hormones that your body naturally produces. When your doctor prescribes an inhaled corticosteroid, they are giving a very small amount of this same hormone, to reduce the inflammation in the airways.

Other Controller Medications

Sometimes, moderate doses of inhaled steroids alone do not fully control asthma symptoms. You may find that, even though you’re taking inhaled steroids regularly, you still experience asthma symptoms, for example, at night or when you exercise.

Long-acting bronchodilators do not work on inflammation directly. Instead, they help the airways relax, allowing more air to pass through.

Long-acting inhaled beta2-agonists (LABAs), long-acting anticholinergic bronchodilators, long-acting muscarinic receptor antagonists (LAMAs), and theophylline are four different types of long-acting bronchodilators. They all work in slightly different ways but produce a similar effect — they relax (dilate) the airway for up to 24 hours. All of these long-acting bronchodilators must always be used together with inhaled corticosteroids. You may be given the inhaled corticosteroid and the bronchodilator in two separate inhalers. If this happens, make sure you use both.

There are several different kinds of long-acting bronchodilators. If you are given the inhaled corticosteroid and LABA in two separate inhalers, make sure you use them both. LABAs are not intended to be used alone for the treatment of asthma. Like any medication, a long-acting bronchodilator should be used only as your doctor advises.

Examples of long-acting bronchodilators are:

  • Formoterol (sold as Oxeze® or Foradil®)
  • Salmeterol (sold as Serevent®)

Possible side effects of long-acting bronchodilators include:

  • Increased heart rate
  • Headache
  • Anxiety
  • Tremor

Some pharmaceutical manufacturers have combined two controller medications into one inhaler. These inhalers are referred to as “Combination Medications”.

Combination medications combine two medications — a corticosteroid plus a bronchodilator (usually a LABA) — in one inhaler. The bronchodilator opens your airways, making it easier for you to breathe. The inhaled corticosteroid reduces inflammation in your airways. Recent studies show that many people with asthma find that combination medications give them better control and are convenient to use.

Examples of combination medications are:

Combination Medications    Corticosteroids    Long-Acting Bronchodilators    
Symbicort®Budesonide (Pumicort®)Formoterol (Oxeze®)
Advair®Fluticasone (Flovent®)Salmeterol (Severent®)

Possible side effects of combination medications include:

  • Rapid heart beat
  • Cough, throat irritation
  • Hoarseness

Leukotriene receptor antagonists, called LTRAs for short, are a class of oral medication that is non-steroidal. They may also be referred to as anti-inflammatory bronchoconstriction preventors. LTRAs work by blocking a chemical reaction that can lead to inflammation in the airways. Although not preferred first choice therapy. LTRAs can also be used when an inhaled corticosteroid cannot, or will not, be used.

If you’ve been taking inhaled steroids and your asthma still isn’t well-controlled, your doctor may prescribe LTRAs instead of increasing the dosage of your inhaled steroids.

LTRAs do not contain steroids; they come in pill formats (including chewable tablets or liquid for children) and have few side effects. LTRAs may also be prescribed to treat allergic rhinitis. If there is no improvement in your symptoms after 4 weeks of use, your doctor will change your treatment.

Examples of LTRAs include:

  • Montelukast (sold as Singulair®)
  • Zafirlukast (sold as Accolate®)

The side effects of LTRAs include:

  • Nausea
  • Headache

Anti-IgE treatment might be recommended if you have allergic asthma and you keep experiencing persistent symptoms despite taking your controller medications.

If you have allergic asthma (about 60% of asthma is caused by allergy), your symptoms are triggered when you inhale certain allergens in the air. These allergens cause a chain reaction that leads to inflammation in the lungs.

While inhaled steroids work by treating and reducing the inflammation, anti-IgE therapy works by keeping inflammation from developing in the first place. It does so by blocking immunoglobulin E, a substance in the body that is one of the underlying causes of inflammation in allergic asthma.

Anti-IgE therapy is only available by prescription. Unlike other asthma medications, it is not administered by pill or by inhaler. It needs to be injected once every two or four weeks by a doctor or other trained healthcare professional.

The only anti-IgE therapy available in Canada is omalizumab (Xolair®).

The most common side effects of anti-IgE therapy are: skin irritation or reaction at the site of the injection, and respiratory tract infections (e.g., common cold).

Who is Anti-lgE therapy for?

Anti-IgE therapy with omalizumab is for adults and adolescents (12 years of age and above) with moderate-to-severe, persistent allergic asthma who continue to have asthma symptoms even though they are taking inhaled steroids.

How quickly does anti-lgE therapy work?

It does take time for the IgE blocking to start working. It is normal not to feel a difference right away. It is important to keep getting your injections until your doctor tells you otherwise. In scientific studies testing omalizumab, the benefits of IgE therapy were shown in most patients by three months.

Does omalizumab (Xolair®) have any serious side effects?

In scientific studies, cancer was seen in a small number of patients receiving omalizumab, as well as in those receiving placebo injections. The rate was higher in patients treated with omalizumab than placebo (0.5% vs. 0.2%). This difference has not been conclusively linked to the omalizumab. Some patients in the studies had a serious allergic reaction called anaphylaxis. This was rare, occurring in less than 0.1% of patients. Doctors have been advised to observe patients for a period after omalizumab injection to make sure that no anaphylaxis develops. If it does, it can be treated.

Will I still need to keep taking my inhalers?

Yes. Anti-IgE therapy is meant to complement, not replace, your existing medications. Although many patients taking IgE therapy have been able to have the dose of their inhaled steroid decreased over time, you will still need to keep taking your other asthma medications as directed by your doctor.

How often is omalizumab given?

Depending on your body’s IgE level and your body weight, omalizumab will be given once every two or four weeks.

Who will administer the injection?

Omalizumab needs to be injected by a trained healthcare professional. You may be able to have it done at your usual doctor’s office. In some cases, your doctor will refer you to another location to have the injection given. There are specialty clinics in many Canadian cities that have been especially set up to give injections of omalizumab.

Occasionally, doctors will prescribe oral (tablet or liquid) corticosteroids for more severe or troublesome asthma symptoms.

Oral corticosteroids can have serious side effects if used for a long time. However, they also have significant benefits that can outweigh their negative side effects. Speak with your healthcare professional who can explain the pros and cons of using oral corticosteroids.

Examples of oral corticosteroids are:

  • Prednisolone (sold as Pediapred®)
  • Prednisone (sold as Deltasone®)

Possible side effects of long-term oral corticosteroid use include:

  • Water retention
  • Bruising
  • Puffy face
  • Increased appetite
  • Weight gain
  • Stomach irritation
  • Mood changes
  • Fractures

Theophyllines are occasionally used to treat asthma. However, their anti-inflammatory properties haven’t yet been conclusively proven and they’re known to have a number of side effects.

Examples of theophyllines are:

  • Slo-Bid®
  • Uniphyl®

Possible side effects of theophyllines include:

  • Headache
  • Insomnia
  • Nausea
  • Vomiting
  • Irritability
  • Stomach upset

Have Questions?

Contact our free Asthma & Allergy Helpline to speak with a Certified Respiratory Educator who can provide you with personalized support.


Learn about reliever (rescue) medications/inhalers; what they are, how they should be used, proper asthma management and more.


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Breathe Easy: Medications

Download a copy of our Breathe Easy Booklet Series on asthma treatments and medications. It provides useful information about finding the different asthma treatment options that are available to you. [Click here to download in French].