Asthma Inhalers: Your Complete Guide to Relievers, Preventers and Combination Inhalers
▶ Asthma inhalers: the key facts
There are three main types of asthma inhaler: reliever inhalers (blue, short-acting bronchodilators for acute symptoms), preventer inhalers (brown/orange, inhaled corticosteroids taken daily), and combination inhalers (containing both a steroid and a long-acting bronchodilator). Most people with asthma need both a reliever and a preventer. Using your reliever more than twice a week suggests your asthma needs better long-term control.
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Asthma inhalers fall into several categories based on how they work and when they are used. Understanding the difference is essential for using them correctly — and for knowing what to do in an acute attack versus how to maintain long-term control.
| Type | Also Known As | When Used | Examples |
|---|---|---|---|
| SABA | Reliever / blue inhaler | On-demand for acute symptoms | Ventolin, Salamol, Bricanyl |
| ICS | Preventer / steroid inhaler | Daily, even when well | Clenil, Pulmicort, Flixotide |
| ICS+LABA | Combination inhaler | Daily maintenance | Fostair, Seretide, Symbicort |
| LABA | Long-acting bronchodilator | Add-on to ICS only (never alone) | Serevent, Oxis |
| LAMA | Long-acting muscarinic antagonist | Add-on therapy in step 4+ | Spiriva Respimat |
| LTRA | Leukotriene receptor antagonist (oral) | Add-on in step 3+ | Montelukast (tablet) |
Reliever Inhalers (SABA)
Reliever inhalers contain a short-acting beta-2 agonist (SABA), most commonly salbutamol. They act by stimulating beta-2 receptors in the airway smooth muscle, causing rapid relaxation and bronchodilation. Symptoms begin to improve within 2–5 minutes of inhalation, and the effect lasts 4–6 hours.
Reliever inhalers are for on-demand use only — they should be taken when symptoms occur, not on a regular schedule. They are not anti-inflammatory and do not treat the underlying cause of asthma. Over-reliance on a reliever (more than twice per week) is a sign that asthma is not adequately controlled and a preventer should be considered or optimised.
Always carry your blue inhaler. A reliever inhaler should be with you at all times in case of an acute attack. Using it more than twice per week is a red flag — speak to your GP or pharmacist about adding or stepping up preventer therapy.
Reliever Inhaler
Ventolin Evohaler 100mcg
Salbutamol pMDI. First-line reliever for acute asthma symptoms and exercise-induced bronchoconstriction.
View & Order →Reliever Inhaler
Salamol Easi-Breathe 100mcg
Breath-actuated salbutamol inhaler. Easier to use than a standard pMDI — ideal if coordination is difficult.
View & Order →Preventer Inhalers (ICS)
Preventer inhalers contain an inhaled corticosteroid (ICS). Unlike reliev inhalers, they do not work immediately — they reduce airway inflammation over days to weeks of regular use. This is why they must be taken every day, even when you feel perfectly well. Stopping a preventer when symptoms are absent is a common and dangerous mistake.
Common ICS inhalers used in the UK include:
- Beclometasone (Clenil Modulite, QVAR) — available in 50mcg, 100mcg, and 200mcg strengths. First-line preventer in many guidelines.
- Budesonide (Pulmicort) — available as a Turbohaler DPI. Also available as a nebuliser solution.
- Fluticasone propionate (Flixotide) — available as a pMDI or Accuhaler. Approximately twice as potent as beclometasone per microgram.
- Ciclesonide (Alvesco) — a prodrug activated in the lungs; may cause fewer oral side effects.
Side effects of inhaled corticosteroids at standard doses are generally minimal. The most common local effects are oral thrush (candidiasis) and hoarseness — rinsing your mouth and gargling after each dose reduces this risk. Using a spacer also reduces oropharyngeal deposition and side effects.
ICS safety: At doses used for asthma, inhaled corticosteroids have a very good safety profile. The small systemic absorption is far outweighed by the benefit of asthma control. However, at high doses over many years, some adrenal suppression and effects on bone density are possible — your GP will monitor you.
Combination Inhalers (ICS+LABA)
If a preventer inhaler alone does not provide adequate asthma control, guidelines recommend adding a long-acting beta-2 agonist (LABA). Rather than using two separate inhalers, a combination inhaler containing both an ICS and a LABA is usually preferred for convenience and to ensure both drugs are taken.
Important combination inhalers used in the UK:
Fostair (beclometasone + formoterol)
Available as pMDI or Nexthaler. Contains extra-fine particles for deeper lung deposition. Can also be used as MART (Maintenance and Reliever Therapy).
Seretide (fluticasone + salmeterol)
Available as Evohaler (pMDI) or Accuhaler (DPI). Once or twice daily. Widely used and well-established.
Symbicort (budesonide + formoterol)
Available as Turbohaler DPI. Can be used as MART, allowing patients to use one inhaler as both preventer and reliever.
Relvar Ellipta (fluticasone furoate + vilanterol)
Once-daily Ellipta DPI. Fluticasone furoate is a next-generation ICS with once-daily dosing.
LABAs must never be used alone without an ICS in asthma. Using a LABA without an ICS is associated with increased risk of severe asthma exacerbations and death. They are only safe in combination with an inhaled corticosteroid.
LAMA Inhalers
Long-acting muscarinic antagonists (LAMAs) work by blocking muscarinic receptors in the airways, reducing bronchoconstriction and mucus secretion. Originally developed for COPD, tiotropium (Spiriva Respimat) is also licensed as add-on therapy in step 4 asthma in adults aged 18+ who are not controlled on ICS+LABA. LAMAs are inhaled once daily.
Inhaler Devices: pMDI, DPI and SMI
The same drug can be delivered in several different device types. The “right” device depends on your ability to use it correctly, your preferences, and environmental considerations:
| Device | Description | Key Points |
|---|---|---|
| pMDI (pressurised metered-dose inhaler) | Classic aerosol canister in a plastic holder. Press and inhale simultaneously. | Requires good hand-breath coordination. Use with a spacer. Lower carbon footprint with HFA propellants being updated to lower-GWP alternatives. |
| DPI (dry powder inhaler) | Breath-actuated — activated by your own inhalation effort. Various formats: Accuhaler, Turbohaler, Ellipta, Nexthaler. | No propellant needed. Requires adequate inspiratory flow (not ideal for acute severe attacks). Lower carbon footprint. |
| SMI (soft mist inhaler) | Produces a slow-moving aerosol cloud. e.g. Spiriva Respimat. | Slower aerosol velocity than pMDI — easier to coordinate. No propellant. |
| Breath-actuated pMDI | Automatically fires on inhalation. e.g. Salamol Easi-Breathe, Autohaler. | Eliminates coordination problem. Good for those who struggle with standard pMDI technique. |
Spacers — Why and How to Use One
A spacer is a plastic chamber that attaches to your pMDI and holds the aerosol cloud for 3–5 seconds while you inhale slowly. Spacers are recommended for all pMDI users and are particularly important for:
- Children (who may struggle to coordinate pressing and inhaling simultaneously)
- Anyone who finds coordination difficult
- People using high-dose ICS (spacers reduce oral steroid deposition and thrush risk)
- During acute asthma attacks (spacer + reliever is as effective as a nebuliser in most cases)
To use a spacer: shake your inhaler, attach it to the spacer, press once, then breathe in slowly and deeply through the mouthpiece. Hold for 5–10 seconds, then breathe out. One puff at a time — do not press the inhaler twice into the spacer before inhaling.
Keep your spacer clean. Wash monthly in warm soapy water, allow to air dry (do not rub dry — this creates static). Replace every 6–12 months or sooner if visibly cracked or damaged.
Choosing the Right Inhaler
The best inhaler is the one you can use correctly and consistently. When switching or starting a new inhaler, ask your pharmacist or practice nurse to check your technique — inhaler errors are common and significantly reduce effectiveness. Key considerations include:
- Can you coordinate pressing and inhaling? If not, consider a DPI or breath-actuated pMDI
- Do you have adequate inspiratory flow? DPIs require a strong, fast inhalation — not suitable if very breathless
- Environmental impact: DPIs and SMIs have lower carbon footprints than standard pMDIs — relevant to NHS sustainability targets
- Portability and convenience: Some formats are more discreet or compact than others
- Cost: Discuss with your GP or pharmacist — all effective inhalers are available on NHS prescription
For a comprehensive overview of asthma — causes, symptoms, diagnosis and all treatment options — see our complete asthma condition guide. [Pillar page — link to be activated on publication]
Frequently Asked Questions
What is the difference between a reliever and a preventer inhaler?
A reliever inhaler (usually blue) contains salbutamol, a short-acting bronchodilator that works within minutes to open the airways. It is used on-demand for acute symptoms. A preventer inhaler contains an inhaled corticosteroid that reduces airway inflammation over time. It must be taken every day — even when you feel well — and takes days to weeks to reach full effect. Preventers are not for acute attacks.
What is a combination inhaler?
A combination inhaler contains both an inhaled corticosteroid (ICS) and a long-acting bronchodilator (LABA). Examples include Fostair, Seretide, and Symbicort. They are used when a preventer inhaler alone is not giving adequate control, and are usually taken once or twice daily. They are not reliever inhalers and should not be used for acute attacks (unless prescribed as MART therapy).
Can I get an asthma inhaler online?
Yes. Reliever inhalers such as Ventolin (salbutamol) and Salamol can be prescribed online following a GPhC-regulated consultation at Access Doctor. Preventer inhalers typically require an initial GP diagnosis, though repeat prescriptions may be available online. Our prescribers follow NICE guidelines and can advise on the most appropriate inhaler for your situation.
What does a blue inhaler do?
A blue inhaler is a reliever inhaler containing salbutamol (e.g. Ventolin). It acts within 2–5 minutes to relax the muscles around the airways, widening them and making breathing easier. It provides temporary relief but does not treat underlying inflammation. If you are using your blue inhaler more than twice a week, this indicates your asthma needs better long-term control — speak to your GP.
Do I need a spacer with my inhaler?
A spacer is strongly recommended for use with pressurised metered-dose inhalers (pMDIs). It holds the aerosol while you inhale slowly, improving delivery to the lungs and reducing side effects. Spacers are particularly important for children, for anyone who finds coordination difficult, and for anyone using high-dose inhaled corticosteroids. They are available free on NHS prescription.
References
- NICE (2024). Asthma: diagnosis, monitoring and chronic asthma management. NG245. nice.org.uk/guidance/ng245
- SIGN/BTS (2023). British Guideline on the Management of Asthma. SIGN 158.
- NHS (2023). Asthma inhalers. nhs.uk/conditions/asthma/treatment
- Asthma + Lung UK (2024). Types of asthma inhalers.
- Usmani OS et al. (2018). Critical inhaler errors in asthma and COPD. npj Primary Care Respiratory Medicine.