What is Symbicort?
Symbicort is a combination inhaler containing budesonide (an inhaled corticosteroid) and formoterol (a long-acting beta2-agonist) used for the long-term maintenance treatment of asthma and COPD. 1
Medication Components
Symbicort combines two active medications in a single inhaler:
Budesonide: An inhaled corticosteroid (ICS) that reduces airway inflammation, addressing the underlying inflammatory process in asthma and COPD 1
Formoterol fumarate dihydrate: A long-acting beta2-agonist (LABA) that relaxes airway smooth muscle for at least 12 hours, preventing and relieving bronchospasm with rapid onset of action 1
Available Formulations
Symbicort comes in two strengths as a hydrofluoroalkane (HFA) pressurized metered-dose inhaler 1:
- Symbicort 80/4.5: Delivers 80 mcg budesonide and 4.5 mcg formoterol per actuation
- Symbicort 160/4.5: Delivers 160 mcg budesonide and 4.5 mcg formoterol per actuation
Both are available in canisters containing 60 or 120 actuations 1.
Clinical Indications
For Asthma
Symbicort is indicated for long-term maintenance treatment of asthma in patients ≥6 years of age whose asthma is not adequately controlled on an ICS alone 1. The combination is specifically for patients who need both an inhaled corticosteroid and a long-acting bronchodilator 2, 3.
Guidelines recommend ICS/LABA combination therapy as preferred treatment for:
- Adults and children >5 years with moderate persistent asthma (Step 3 care) 2, 4
- Patients with two or more exacerbations annually 5
For COPD
Symbicort 160/4.5 is used long-term (2 inhalations twice daily) to improve symptoms and reduce exacerbations in patients with COPD 1. Combination ICS/LABA therapy in COPD reduces exacerbation frequency compared to LABA alone, though it increases pneumonia risk by 4% 5.
Mechanism of Action
The two components work synergistically through complementary mechanisms 1:
Budesonide exhibits potent glucocorticoid activity with approximately 200-fold higher affinity for the glucocorticoid receptor than cortisol. It inhibits multiple inflammatory cell types (mast cells, eosinophils, neutrophils, macrophages, lymphocytes) and mediators involved in airway inflammation 1.
Formoterol is a selective beta2-adrenergic agonist that activates beta2-receptors on airway smooth muscle, causing bronchodilation with rapid onset (within 1-3 minutes) and sustained duration (≥12 hours) 1.
Clinical Evidence
Studies demonstrate that budesonide/formoterol combination therapy:
- Reduces moderate and severe exacerbations more effectively than either component alone 5
- Improves lung function, quality of life, and symptom control better than higher-dose ICS monotherapy 6, 3
- In the FACET study, reduced mild exacerbations by 40% and severe exacerbations by 29% when added to low-dose ICS 6
- Shows similar efficacy to fluticasone/salmeterol combinations 5, 7
Important Safety Considerations
Critical Warning: Long-acting beta-agonists like formoterol, when used alone, increase the risk of asthma-related hospitalization and death. Symbicort should NEVER be used as monotherapy—the ICS component is essential for safety 2, 8, 1.
Other key safety points:
- Not for acute symptoms: Symbicort is maintenance therapy only; use a short-acting beta-agonist (like albuterol) for acute symptom relief 1
- Pneumonia risk: ICS therapy increases pneumonia risk in COPD patients (OR 1.38-1.48) 5
- Local effects: Can cause oral candidiasis (thrush); rinse mouth after use 1
- Systemic corticosteroid effects: May cause hypercorticism, adrenal suppression, reduced bone mineral density, and growth suppression in children with prolonged use 1
Dosing Approach
Standard dosing is twice daily, with the specific strength and number of inhalations determined by asthma severity 1. Prime the inhaler before first use and after 7 days of non-use by releasing two test sprays 1.
In some countries outside the U.S., budesonide/formoterol is used in a "maintenance and reliever therapy" (MART) regimen, where the same inhaler serves both maintenance and rescue purposes, which has shown reduced exacerbation rates 9, 10, 11. However, this approach is not FDA-approved in the United States 1.
Common Pitfalls to Avoid
- Never use as rescue medication in the U.S.: Patients need a separate short-acting bronchodilator for acute symptoms 1
- Don't add other LABAs: Using multiple LABA medications increases adverse effects without additional benefit 1
- Don't stop abruptly: Taper under physician guidance to prevent symptom recurrence and potential adrenal crisis 1
- Monitor for increasing SABA use: If patients need their rescue inhaler >2 days/week, their asthma is inadequately controlled and requires treatment adjustment 2, 1