Symbicort: Uses, Dosage & Side Effects

What Is Symbicort and What Is It Used For?

Symbicort contains two complementary active substances that together treat the two main mechanisms driving asthma and chronic obstructive pulmonary disease (COPD): airway inflammation and bronchoconstriction (narrowing of the airways). The two components belong to different pharmacological classes and have different but synergistic mechanisms of action, which is why they are combined in a single inhaler — a strategy endorsed by the Global Initiative for Asthma (GINA) and the Global Initiative for Chronic Obstructive Lung Disease (GOLD) as the cornerstone of modern obstructive airways disease management.

Budesonide is a potent glucocorticosteroid that exerts its anti-inflammatory effects locally in the airways. When inhaled regularly, budesonide binds to intracellular glucocorticoid receptors, which then translocate to the cell nucleus and modulate the transcription of hundreds of genes involved in the inflammatory response. This leads to decreased production of pro-inflammatory cytokines, chemokines and leukotrienes; reduced recruitment and activation of inflammatory cells including eosinophils, mast cells, T lymphocytes, macrophages and neutrophils; decreased mucus hypersecretion; and reduced airway hyperresponsiveness. The anti-inflammatory effects of budesonide are not immediate; regular daily use over several days to weeks is required to achieve and maintain optimal disease control. This is why Symbicort must be used consistently, even during symptom-free periods.

Formoterol fumarate dihydrate is a highly selective long-acting beta2-adrenergic agonist (LABA). It stimulates beta2-adrenergic receptors in bronchial smooth muscle, activating adenylyl cyclase, increasing intracellular cyclic adenosine monophosphate (cAMP) levels, and ultimately causing smooth-muscle relaxation and bronchodilation — a widening of the airways that allows more air to flow in and out of the lungs. A distinctive pharmacological feature of formoterol compared with other LABAs such as salmeterol is its rapid onset of action: bronchodilation begins within 1 to 3 minutes of inhalation and lasts at least 12 hours. This combination of fast onset and long duration is what makes formoterol especially suitable for a single-inhaler maintenance and reliever regimen.

When budesonide and formoterol are delivered together in Symbicort, the two active ingredients provide complementary benefits that are greater than either component alone. The ICS component addresses the underlying inflammatory process that drives airway remodelling, hyperreactivity and exacerbations, while the LABA component provides sustained bronchodilation, keeping the airways open and making breathing easier throughout the day and night. Large randomized controlled trials and meta-analyses have demonstrated that ICS/LABA combinations reduce the frequency of asthma and COPD exacerbations, improve lung function (as measured by FEV1 and PEF), reduce symptom scores, and improve health-related quality of life compared with ICS alone or LABA alone.

Indications for Symbicort

Symbicort is approved for the following conditions, with specific indications varying slightly between regulatory authorities (EMA, FDA, TGA):

• Asthma: Regular treatment of asthma in adults and, depending on formulation and jurisdiction, in adolescents and children aged 6 years and over, where use of a combination product (inhaled corticosteroid plus long-acting beta2-agonist) is appropriate. This includes patients not adequately controlled with inhaled corticosteroids and as-needed short-acting beta2-agonists, as well as patients already adequately controlled on both an ICS and a LABA. Certain Symbicort Turbuhaler strengths are additionally indicated for maintenance and reliever therapy (MART / SMART), where the same inhaler is used for both daily maintenance and as needed for symptom relief.
• Chronic Obstructive Pulmonary Disease (COPD): Symptomatic treatment of patients with COPD, typically those with a post-bronchodilator FEV1 less than 70 percent of predicted normal and a history of repeated exacerbations despite regular therapy with long-acting bronchodilators. In COPD, the ICS component reduces exacerbation frequency, while the LABA provides sustained bronchodilation and symptom relief.

Symbicort Device Formats

Symbicort is marketed in two principal device formats, each with different characteristics and patient suitability. Choosing the right device is essential for ensuring good inhaler technique and effective drug delivery.

The Turbuhaler is a multi-dose dry powder inhaler that has been on the market for decades. It is taste-free, odorless and contains only micronised active drug with no added carriers in the inhaled dose, meaning that many patients do not perceive the inhalation of the medication. This is a normal characteristic of the device and does not indicate that the dose has not been taken. The built-in dose counter shows how many doses remain. The Rapihaler (also known as Symbicort HFA or Symbicort pMDI in various markets) is a pressurized metered-dose inhaler that uses a hydrofluoroalkane (HFA) propellant to deliver a fine aerosol spray. It is preferred for patients who cannot generate a strong inspiratory flow, such as young children, frail elderly patients, or those with severe airway obstruction, and it can be used with a spacer device to improve lung deposition and reduce oropharyngeal deposition.

What Should You Know Before Taking Symbicort?

Contraindications

Symbicort is contraindicated in patients with known hypersensitivity to budesonide, to formoterol fumarate dihydrate, or to any of the excipients. The Turbuhaler formulation contains lactose monohydrate as a carrier; while the quantity is very small, patients with severe lactose intolerance or known allergy to milk proteins should discuss this with their doctor before use. The Rapihaler (pMDI) does not contain lactose but uses HFA-227 (norflurane) as the propellant, which is generally well tolerated. Allergic reactions to inhaled medications can manifest as paradoxical bronchospasm (sudden tightening of the airways), skin rash, urticaria (hives), itching, or angioedema (swelling of the face, lips, tongue or throat). If you experience any of these symptoms, stop using Symbicort and seek medical attention immediately.

Warnings and Precautions

Before starting Symbicort, inform your healthcare provider about all medical conditions you have or have had, as they may require special monitoring, dose adjustments, or additional precautions. Key conditions to disclose include:

• Cardiovascular disease: Formoterol, like other beta2-agonists, can cause cardiovascular effects including increased heart rate (tachycardia), palpitations, chest pain, and changes in blood pressure. Patients with coronary artery disease, heart rhythm disorders (arrhythmias such as atrial fibrillation or supraventricular tachycardia), hypertrophic obstructive cardiomyopathy, aortic stenosis, severe heart failure, or other significant cardiovascular conditions should use Symbicort with caution and under close medical supervision. Congenital or acquired QTc prolongation is a particular concern because formoterol can itself modestly prolong the QTc interval.
• Diabetes mellitus: High doses of beta2-agonists can temporarily increase blood glucose levels due to glycogenolysis. Patients with diabetes should monitor their blood glucose more carefully when starting Symbicort or changing doses, as adjustments to antidiabetic medications may be required.
• Thyroid disorders: Beta2-agonists may exacerbate the cardiovascular symptoms of untreated or poorly controlled thyrotoxicosis. Euthyroid status should be achieved before starting regular therapy when possible.
• Low potassium (hypokalemia): Beta2-agonists can cause a dose-related decrease in serum potassium. This effect may be compounded by concomitant treatment with xanthine derivatives (e.g., theophylline), systemic corticosteroids, or potassium-losing diuretics. Severe hypokalemia can potentially cause cardiac arrhythmias. Serum potassium levels should be monitored in patients at risk, particularly during severe asthma exacerbations when hypoxia may worsen the effects of hypokalemia.
• Adrenal insufficiency: Patients transferring from long-term systemic (oral) corticosteroids to inhaled corticosteroids may have suppressed hypothalamic–pituitary–adrenal (HPA) function. The transition should be gradual, with careful monitoring for signs of adrenal insufficiency such as fatigue, weakness, nausea, weight loss, and low blood pressure, particularly during periods of physiological stress (surgery, trauma, severe illness). In such situations, temporary supplementation with a systemic corticosteroid may be required.
• Tuberculosis and respiratory infections: Patients with active or quiescent pulmonary tuberculosis, or untreated fungal, viral, or bacterial respiratory infections, should be monitored carefully. Inhaled corticosteroids may suppress local immune defenses in the airways.
• Osteoporosis and bone health: Long-term use of high doses of inhaled corticosteroids may reduce bone mineral density. Patients at risk for osteoporosis (postmenopausal women, elderly patients, those on concomitant systemic corticosteroids, or with a family history of osteoporosis) should be assessed and receive appropriate preventive measures, which may include vitamin D, calcium, weight-bearing exercise and, where indicated, bone-protective therapy.
• Ocular effects: Long-term use of inhaled corticosteroids has been associated with an increased risk of cataracts and glaucoma. Regular eye examinations are recommended, particularly in older adults and those on high-dose therapy.
• Hepatic impairment: In severe hepatic impairment, systemic exposure to budesonide and formoterol may be increased due to reduced hepatic metabolism. Symbicort should be used with caution in these patients.

Pregnancy and Breastfeeding

If you are pregnant, think you may be pregnant, or are planning to become pregnant, consult your doctor before using Symbicort. It is important to understand that uncontrolled asthma during pregnancy carries significant risks for both mother and baby, including pre-eclampsia, intrauterine growth restriction, low birth weight, premature birth, and increased perinatal mortality. Maintaining adequate asthma control during pregnancy is therefore essential and generally outweighs the theoretical risks of inhaled therapy.

Budesonide is among the most extensively studied inhaled corticosteroids in pregnancy. Data from large epidemiological studies and pregnancy registries involving more than 20,000 exposed pregnancies have not demonstrated an increased risk of congenital malformations or other adverse fetal outcomes with inhaled budesonide. International guidelines, including GINA, recommend that pregnant women with asthma continue their controller therapy (including ICS) to prevent exacerbations. Data on formoterol use during pregnancy are more limited but have not revealed concerning signals in animal reproductive studies at clinically relevant doses. As a precaution, Symbicort should be used during pregnancy only when the expected benefit to the mother justifies any potential risk to the fetus, typically at the lowest effective dose.

Budesonide is excreted in breast milk, but at therapeutic inhaled doses the amount reaching the nursing infant is expected to be negligible and well below the level that would produce any systemic pharmacological effect. Formoterol excretion in human breast milk has not been specifically studied, but it is excreted in the milk of lactating rats at very low concentrations. In general, asthma controllers, including Symbicort, are considered compatible with breastfeeding, and a decision to continue Symbicort during lactation should weigh the benefit of breastfeeding to the child against the benefit of continued treatment for the mother.

Children and Adolescents

Approval for paediatric use of Symbicort varies by formulation and jurisdiction. The Symbicort Turbuhaler 80/4.5 mcg and, in many countries, the 160/4.5 mcg strength are approved for children aged 6 years and older for maintenance asthma therapy; some strengths are also approved in adolescents 12 years and older for MART. The Rapihaler/pMDI is often preferred in younger children who cannot reliably generate sufficient inspiratory flow for a dry powder device; a spacer is usually recommended in children under 12 years to improve lung deposition. Specific age indications should be confirmed with your prescriber and local product labelling. Growth velocity should be monitored in children and adolescents on long-term ICS therapy, and the lowest effective dose that maintains control should always be used.

Driving and Operating Machinery

Symbicort is not known to affect the ability to drive or operate machinery in most patients. However, if you experience side effects such as dizziness, tremor, blurred vision, or palpitations that could impair your performance, you should refrain from driving or operating heavy machinery until these symptoms have resolved.

How Does Symbicort Interact with Other Drugs?

Drug interactions with Symbicort can be clinically significant and fall into two broad categories: those affecting the corticosteroid component (budesonide) and those affecting the beta2-agonist component (formoterol). Understanding these interactions is important for the safe and effective use of the medication. Always inform your doctor and pharmacist about all medicines you are taking, including prescription drugs, over-the-counter medicines, herbal supplements, and recreational substances. Some interactions are rare but serious, while others are common and require only routine monitoring.

Major Interactions

The following interactions are considered clinically significant and may require avoidance, dose adjustment, or additional monitoring:

Other Interactions

What Is the Correct Dosage of Symbicort?

Symbicort should always be used exactly as prescribed by your doctor. The appropriate dose depends on the severity of your condition, your current level of control, your age, whether you are being treated for asthma or COPD, the specific formulation (Turbuhaler strength or Rapihaler strength), and the treatment regimen prescribed (fixed dosing versus MART). Symbicort is a maintenance (preventer) medication and should be used regularly every day, even when you feel well. Do not stop using Symbicort abruptly without medical advice, as this may lead to deterioration of your respiratory condition.

Adults with Asthma

In the fixed-dose maintenance approach, Symbicort is taken at a regular dose every day, and a separate rapid-acting bronchodilator (such as salbutamol/albuterol) is used as needed for acute symptom relief. In the maintenance and reliever therapy (MART) approach, also known as SMART (Single Maintenance And Reliever Therapy), the same Symbicort inhaler is used both for the fixed daily maintenance dose and as needed for symptom relief. This approach is supported by multiple randomized controlled trials and recommended by GINA for appropriate patients with asthma. MART has been shown to reduce the risk of severe exacerbations compared with fixed-dose ICS/LABA plus short-acting beta2-agonist reliever. Not all Symbicort formulations are licensed for MART in every country, and specific instructions should come from your prescribing physician.

Adults with COPD

In COPD, the benefit of ICS-containing therapy is primarily a reduction in the frequency of exacerbations. According to GOLD 2024, ICS/LABA combinations are recommended in patients with a history of exacerbations despite appropriate bronchodilator therapy, particularly those with blood eosinophils ≥300 cells/µL, in whom the ICS benefit is greatest. In patients with low blood eosinophils and no history of frequent exacerbations, the risk–benefit balance of ICS is less favourable, and periodic review of whether the ICS component remains necessary is recommended.

Children and Adolescents

Symbicort Turbuhaler 80/4.5 mcg (and in many markets 160/4.5 mcg) is approved for the maintenance treatment of asthma in children aged 6 years and older, typically at a dose of 1 to 2 inhalations twice daily. Symbicort Turbuhaler is not recommended for children younger than 6 years. Symbicort Rapihaler/pMDI may be preferred in younger children (usually from age 6, and sometimes as young as 4 in some jurisdictions) who cannot reliably generate the inspiratory flow required for a dry powder inhaler, and is often used with a spacer. Specific paediatric indications depend on local product labelling. The lowest effective dose that maintains asthma control should always be used, and growth velocity should be periodically monitored in children on long-term ICS therapy.

Elderly Patients

No specific dose adjustment is required for elderly patients. However, the elderly may be more susceptible to systemic effects of inhaled corticosteroids (osteoporosis, cataracts, glaucoma, skin thinning) and the cardiovascular effects of beta2-agonists (tachycardia, tremor, arrhythmia). Regular monitoring, including periodic bone mineral density assessments, eye examinations, and cardiovascular review, should be considered for elderly patients on long-term therapy. In patients with significant hepatic impairment, systemic exposure to both components is expected to be increased and caution is advised.

Missed Dose

If you forget to take a dose of Symbicort, take it as soon as you remember. However, if it is almost time for your next scheduled dose, skip the missed dose and take your next dose at the usual time. Do not take a double dose to make up for a forgotten dose. If you frequently forget doses, consider setting a daily alarm, keeping the inhaler in a visible place, or using a medication reminder application. Consistent daily use is essential for achieving and maintaining stable asthma or COPD control, and missed doses are a common cause of poor disease control.

Overdose

An overdose of Symbicort is primarily driven by the formoterol component. Symptoms of formoterol overdose include fine tremor, headache, palpitations, sinus tachycardia, muscle cramps, nausea, and in severe cases metabolic acidosis, hypokalemia, and hyperglycemia. QTc prolongation and ventricular arrhythmias may occur. An overdose of budesonide is unlikely to cause acute clinical problems, but chronic overuse at very high doses may lead to systemic corticosteroid effects such as adrenal suppression and Cushing-like features. In suspected overdose, treatment is supportive and symptomatic. Serum potassium levels and ECG should be monitored in significant overdoses. There is no specific antidote for formoterol or budesonide overdose; in severe cases, a cardioselective beta-blocker may be considered by emergency specialists, balancing the risk of precipitating bronchospasm. Contact your doctor, pharmacist, or local poison control centre for advice.

How to Use the Symbicort Turbuhaler

Correct inhaler technique is critical for ensuring that the medication reaches the lungs effectively. The Turbuhaler is a breath-actuated dry powder inhaler, meaning the dose is released automatically when you inhale forcefully through the device. Follow these steps carefully:

1. Unscrew and remove the white cover from the inhaler. Check the dose counter on the side or the bottom to confirm that doses remain.
2. Hold the inhaler upright with the red grip at the bottom. Do not hold the inhaler by the mouthpiece when loading the dose.
3. Twist the red grip as far as it will go in one direction, then twist it back the other way. You should hear a click. A dose is now loaded. Do not shake the inhaler.
4. Breathe out gently away from the mouthpiece. Do not breathe out into the inhaler, as moisture can damage the powder.
5. Place the mouthpiece between your teeth, close your lips firmly around it, and inhale deeply and forcefully. The powder is taste-free and virtually odorless, so you may not feel the dose — this is normal.
6. Remove the inhaler and hold your breath for approximately 5 to 10 seconds or as long as is comfortable.
7. Replace the cover and tighten it. If a second dose is required, repeat steps 2–6.
8. Rinse your mouth with water after the final inhalation and spit out. Do not swallow the rinse water. This reduces the risk of oral thrush and hoarseness.

How to Use the Symbicort Rapihaler (pMDI)

The Rapihaler is a pressurized metered-dose inhaler that delivers a puff of aerosolized medication when the canister is pressed down. Unlike the Turbuhaler, it does not require a deep, forceful inhalation, and it can be used with a spacer (valved holding chamber) to improve drug delivery. Follow these steps:

1. Remove the cap from the mouthpiece and check that the mouthpiece is clean and free of obstructions.
2. Shake the inhaler vigorously for approximately 5 seconds. Shaking ensures even mixing of the drug suspension.
3. Prime the inhaler if new or unused for more than 7 days: release two test sprays into the air, away from your face, as described in the patient information leaflet.
4. Hold the inhaler upright with your thumb on the base and your index finger on top of the canister.
5. Breathe out gently away from the inhaler until your lungs feel empty.
6. Place the mouthpiece between your lips and seal them around it. Tilt your head slightly back.
7. Begin a slow, deep breath through your mouth, and simultaneously press the canister down to release a puff. Continue breathing in slowly and deeply until your lungs are full.
8. Remove the inhaler and hold your breath for about 10 seconds, then breathe out slowly.
9. Wait about 30 seconds before taking a second puff, if prescribed. Repeat steps 2 through 8.
10. Replace the cap and rinse your mouth with water after the final inhalation.

What Are the Side Effects of Symbicort?

Like all medicines, Symbicort can cause side effects, although not everyone experiences them. The side effects are principally related to its two active components: budesonide (inhaled corticosteroid) and formoterol (long-acting beta2-agonist). Many of the side effects are class effects of these drug categories and are well characterized from decades of clinical experience and post-marketing surveillance. Local side effects from the ICS (throat irritation, oral thrush, hoarseness) can often be minimized through proper inhaler technique and mouth rinsing. Systemic side effects from the LABA (tremor, palpitations, headache) are typically mild and diminish with continued regular use.

Side effects below are categorized by frequency according to MedDRA conventions, derived from clinical trial and post-marketing safety data.

Oral candidiasis is the most commonly reported side effect of budesonide-containing inhalers. It occurs when the corticosteroid deposited in the oropharynx suppresses local immune defenses and allows overgrowth of the commensal fungus Candida albicans. The risk of oral candidiasis can be substantially reduced by three measures: rinsing the mouth thoroughly with water and spitting it out after each inhalation; brushing the teeth after inhalation when possible; and using a spacer with the pMDI formulation. If oral thrush develops despite these measures, it can usually be treated effectively with a topical antifungal (e.g., nystatin suspension or miconazole oral gel) or oral fluconazole, as prescribed by your doctor.

Tremor, palpitations and headache are common class effects of beta2-agonists like formoterol, reflecting stimulation of beta2-receptors in skeletal muscle and the cardiovascular system. These effects are usually mild, dose-related, and tend to diminish over the first days to weeks of regular use as tolerance develops. If they are troublesome or persistent, discuss with your doctor whether a dose adjustment or formulation change is appropriate.

Pneumonia has been observed at an increased rate in randomized trials of inhaled corticosteroids in COPD, including trials of budesonide-containing combinations. The GOLD guidelines acknowledge this class-effect risk and recommend that clinicians weigh the benefits of ICS therapy (reduced exacerbations) against the pneumonia risk in each individual patient. COPD patients on ICS should be monitored for signs of pneumonia, and the distinction between a COPD exacerbation and pneumonia can be challenging clinically; radiographic imaging is often required.

How Should You Store Symbicort?

Proper storage is essential to maintain the quality, dose accuracy, and safety of Symbicort. Storage requirements differ slightly between the Turbuhaler (dry powder) and the Rapihaler (pressurized metered-dose inhaler) because they use different formulations and delivery mechanisms.

Turbuhaler (Dry Powder Inhaler)

• Temperature: Store below 30°C. Do not refrigerate or freeze, as this can damage the inhaler mechanism and the powder.
• Protect from moisture: Always keep the protective white cover tightly closed when the inhaler is not in use. Humidity and moisture can cause the powder to clump and reduce the delivered dose. Avoid storing the inhaler in bathrooms or other humid areas.
• Shelf life after first opening: The inhaler is typically stable until the labelled expiration date when stored correctly, but once the foil pouch is opened (if supplied), use within the timeframe specified on the packaging (often 3 months).
• Expiration date: Do not use after the expiration date printed on the carton and inhaler. The expiration date refers to the last day of that month.

Rapihaler (Pressurized Metered-Dose Inhaler)

• Temperature: Store below 30°C (do not exceed 50°C). Do not refrigerate or freeze. Do not expose to direct sunlight or high heat (e.g., the glove box of a car in summer).
• Pressurized canister safety: The canister contains a pressurized HFA propellant. Do not puncture, pierce, burn, or incinerate the canister even when empty, as it may explode.
• Protect from extreme cold: If the canister becomes cold (below approximately 5°C), it may not deliver a consistent dose. Allow it to return to room temperature and gently shake before use.
• Priming: If the Rapihaler is new or has not been used for more than 7 days (or as specified in the patient information leaflet), release test sprays into the air before use to ensure accurate dose delivery.
• Expiration date: Do not use after the expiration date printed on the canister and carton.

General Storage Principles

• Keep out of reach of children: Store all inhalers in a safe location where young children cannot access them.
• Travel: When travelling with Symbicort, keep the inhaler in your hand luggage where temperatures are more controlled. Avoid leaving the inhaler in hot vehicles or exposed to direct sunlight. On aircraft, pressurized metered-dose inhalers are permitted in both hand and checked luggage, but hand luggage is strongly recommended.
• Disposal: Do not dispose of inhalers via household waste, sewage, or fire. Return unused or expired inhalers to a pharmacy for appropriate disposal, which is environmentally important given the greenhouse-gas footprint of HFA propellants in pMDIs.

What Does Symbicort Contain?

Active Ingredients

Symbicort contains two active substances that work together to treat asthma and COPD:

Lactose monohydrate in the Turbuhaler serves as a carrier that helps the fine drug particles flow through the device and be deposited consistently in the airways during inhalation. The lactose used in dry powder inhalers contains trace amounts of milk proteins. Although the quantity is very small and unlikely to cause problems for most people, patients with severe lactose intolerance or known allergy to milk proteins should discuss this with their doctor before using the Turbuhaler; the Rapihaler is a lactose-free alternative.

HFA-227 (apaflurane) in the Rapihaler is a hydrofluoroalkane propellant that replaces older ozone-depleting chlorofluorocarbons (CFCs) used in earlier metered-dose inhalers. HFA propellants do not damage the ozone layer but do have a greenhouse-gas global warming potential; this has prompted increased interest in dry powder inhalers and propellant-free alternatives, although the clinical decision between pMDI and DPI must always prioritize the device best suited to the individual patient.

Appearance and Pack Sizes

The Symbicort Turbuhaler is a white plastic inhaler with a red grip base and a protective white cover, containing either 60 or 120 metered doses (depending on strength and market). A dose counter is visible through a window on the side or the bottom of the inhaler.

The Symbicort Rapihaler (pMDI) consists of a pressurized aluminium canister housed in a plastic actuator with a dust cap. It typically contains 120 actuations (about one month's supply at 2 inhalations twice daily) and in many markets incorporates a dose counter on the actuator. Pack sizes vary by country; check your local packaging for specific contents.

Marketing Authorization

Symbicort is developed and marketed globally by AstraZeneca. It received its initial marketing authorization in Europe in 2000 for the Turbuhaler format and is now registered in more than 120 countries under the brand names Symbicort, Symbicort Turbuhaler, Symbicort Rapihaler, and Symbicort HFA, among others. Generic and biosimilar combinations of budesonide/formoterol are available in several markets under different brand names (e.g., BiResp Spiromax, Bufomix Easyhaler, DuoResp Spiromax). Symbicort and these generic alternatives are therapeutically equivalent when used at equivalent delivered doses.