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Symbicort: 7 things you should know

Medically reviewed by Carmen Fookes, BPharm. Last updated on July 14, 2022.

1. How it works

  • Symbicort is a combination inhaler containing budesonide and formoterol. Budesonide is a corticosteroid that decreases inflammation. When it is used in an inhaler, it specifically and generally only decreases inflammation in the lungs and airways. Budesonide belongs to the class of medicines known as inhaled corticosteroids (ICS). It is specifically a glucocorticoid.
  • Formoterol is a long-acting bronchodilator. Formoterol relaxes muscles in the airways which allows them to open, making breathing easier. Formoterol belongs to the class of medicines known as long-acting beta2-adrenergic agonists (LABA).
  • Symbicort belongs to the class of medicines known as combination LABA/ICS inhalers.

2. Upsides

  • May be used in the treatment of moderate-to-severe asthma in adults and children over the age of six years.
  • A specific strength of Symbicort (160/4.5) may be used as a maintenance treatment in people with chronic obstructive pulmonary disease (COPD) including chronic bronchitis and emphysema, to reduce inflammation and airflow obstruction.
  • Having two medications in one inhaler is more convenient than having to take two inhalers.
  • Having these medications in an inhaled form means they work directly where they need to with less risk of side effects.
  • Symbicort is available as a generic under the name budesonide/formoterol.

3. Downsides

If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

  • Throat irritation, sinusitis, nasopharyngitis (runny or stuffy nose, sneezing), headache, oral thrush, upper and lower respiratory tract infections, and stomach discomfort.
  • Other side effects that are uncommon but may be associated with Symbicort include cataracts, glaucoma, and other eye problems; low potassium levels; and an increase in blood glucose levels.
  • Symbicort does not relieve acute bronchospasm (breathlessness). Although formoterol does open the airways, it takes time to work and Symbicort should never be used for the emergency treatment of asthma. A rescue inhaler, such as albuterol, should always be kept close by to treat sudden symptoms.
  • LABAs, such as formoterol, one of the ingredients in Symbicort, have been associated with an increased risk of asthma-related deaths. It is not known whether concurrent use of inhaled corticosteroids (such as budesonide - also contained in Symbicort) mitigates this risk. For this reason, Symbicort is generally only recommended for people with asthma not adequately controlled with an inhaled corticosteroid or with a disease severity that warrants the addition of an LABA. It should not be initiated in people with deteriorating or life-threatening exacerbations of asthma or COPD. Even once initiated, the need for continued Symbicort based on asthma control should be reassessed at regular intervals by a doctor.
  • May not be suitable for people with certain types of heart disease. Rarely, formoterol has been associated with pulse rate and blood pressure increases, and ECG changes.
  • Corticosteroids, such as budesonide, may decrease your immune response and increase your risk of developing pneumonia or increase the severity of viral infections such as chickenpox and measles. Always make sure you keep your recommended vaccines up to date.
  • Symbicort may interact with several drugs such as ketoconazole, HIV medications, antidepressants, glaucoma treatments, and clarithromycin.
  • Long-term administration of corticosteroids, such as budesonide, is associated with a reduction in bone mineral density. It is not known if this is related to an increase in fracture risk. The risk is greatest in those who are immobile, post-menopausal, with a family history of osteoporosis, who smoke, with a poor diet, or who take other drugs that also reduce bone mass (such as anticonvulsants or oral corticosteroids).
  • Regular administration of corticosteroids, such as budesonide, has been associated with a reduction in growth velocity in children. Growth rates should be monitored if Symbicort is used in children.
  • Although budesonide and formoterol have been associated with adverse effects on the fetus in rodent studies, studies of pregnant women administered inhaled budesonide alone have not shown an increased risk of abnormalities during pregnancy. Research suggests that rodents are more prone to teratogenic effects from corticosteroid exposure than humans. In women with poorly or moderately controlled asthma there is an increased risk of severe perinatal adverse outcomes such as preeclampsia in the mother and prematurity, low birth weight, and small for gestational age in the neonate. There is a risk of beta-agonist interference with uterine contractility during labor and use should be restricted to those for whom the benefits outweigh the risks.

Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects

4. Bottom Line

Symbicort is a combination inhaler that contains budesonide (a corticosteroid) and formoterol (a long-acting bronchodilator). Symbicort should only be used in people with moderate-to-severe asthma that remains uncontrolled despite regular inhaled corticosteroids.

5. Tips

  • Inhale Symbicort exactly as directed by your doctor. The usual dosage is two inhalations, morning and night (12 hours apart). Do not exceed the recommended dose as potentially fatal side effects are more likely.
  • If you develop asthma symptoms in the time between Symbicort dosages, use a short-acting inhaled, beta2-agonist such as albuterol to relieve breathlessness.
  • Rinse the mouth out with water following a dose of Symbicort, then spit the water out (do not swallow). Doing this reduces the risk of oral thrush developing.
  • If you are using Symbicort for the first time, or if it has been dropped or not used for seven days, you will need to prime it. Shake the inhaler well for five seconds then release a test spray. Repeat this process, making sure you point the inhaler in a safe direction and away from the face.
  • Symbicort is available as two different strengths: budesonide 80mcg and formoterol 4.5mcg and budesonide 160mcg and formoterol 4.5mcg. Always make sure you are using the correct strength as prescribed by your doctor.
  • If Symbicort appears to make you more breathless, stop taking it. Inhale a dose of your short-acting bronchodilator instead (such as albuterol and tell your doctor immediately.
  • Always let other health professionals know that you are taking Symbicort. Do not take any other medications, including those bought over-the-counter, before checking that they are compatible with Symbicort.
  • Tell your doctor if you are pregnant or intending to become pregnant before taking Symbicort. Your asthma must be under good control before and during your pregnancy.

6. Response and effectiveness

  • The effectiveness of Symbicort depends on regular usage. An improvement in asthma control may be seen within 15 minutes of treatment; however, it may take up to two weeks before the full benefits are seen. Response times and degree of effectiveness can vary from person to person.
  • Orally inhaled budesonide is rapidly absorbed in the lungs and peak concentrations are usually reached within 20 minutes.
  • Formoterol in a powdered form (as used for inhalation) starts to work within 3 minutes and 80% of the peak effect occurs within 15 minutes. Effects last approximately 12 hours in most people.

7. Interactions

Medicines that interact with Symbicort may either decrease its effect, affect how long it works for, increase side effects, or have less of an effect when taken with Symbicort. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.

Symbicort interacts with over 660 medications; the majority of these interactions are considered major or moderate. Common medications that may interact with Symbicort include:

  • amiodarone
  • antifungals, such as ketoconazole
  • antipsychotics, such as chlorpromazine, clozapine, or haloperidol
  • arthritis treatments, such as leflunomide
  • biologics, such as adalimumab
  • cancer treatments such as idelalisib
  • cyclosporine
  • diabetes medications, such as glipizide, glyburide, glimepiride, or insulin
  • diuretics, such as amiloride, bumetanide, or HCTZ
  • grapefruit juice
  • heart medications such as amiodarone, carteolol, or nadolol
  • HIV medications (eg, atazanavir, cobicistat, delavirdine, efavirenz, indinavir, etravirine, ritonavir, nevirapine, saquinavir, or tipranavir)
  • hormones, such as estradiol
  • JAK inhibitors, such as tofacitinib
  • ketoconazole and other strong CYP3A4 inhibitors (such as ritonavir, clarithromycin, itraconazole, nefazodone)
  • linezolid
  • lithium
  • methotrexate
  • multiple sclerosis treatments, such as fingolimod or ozanimod
  • NSAIDs, such as diclofenac,
  • other long-acting beta-agonists, such as arformoterol, formoterol, or salmeterol
  • sotalol
  • TNF inhibitors, such as etanercept
  • vaccines, such as BCG vaccine, cholera, or typhoid
  • warfarin.

Alcohol can increase the likelihood of side effects of Symbicort such as nausea and vomiting, dizziness, and dry mouth.

Note that this list is not all-inclusive and includes only common medications that may interact with Symbicort. You should refer to the prescribing information for Symbicort for a complete list of interactions.


Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Symbicort only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Copyright 1996-2023 Revision date: July 14, 2022.