Fluticasone/Salmeterol (Seretide 125 Evohaler)
Is It Right for You?
A complete guide to Fluticasone/Salmeterol (Seretide 125 Evohaler) — what it treats, how it works, dosages, side effects, and when a clinician may prescribe it following an online consultation.
What Is Seretide 125 Evohaler?
Seretide 125 Evohaler is a pressurised metered-dose inhaler (pMDI) delivering fluticasone propionate 125 micrograms (an inhaled corticosteroid, ICS) and salmeterol 25 micrograms (a long-acting beta-2 agonist, LABA) per actuation. It is used for the regular maintenance treatment of asthma in adults and adolescents, and for the maintenance treatment of chronic obstructive pulmonary disease (COPD) in adults.
As a pMDI, the Evohaler requires coordinated actuation and inhalation — pressing the canister simultaneously with slow, deep inhalation. A spacer device is strongly recommended, particularly for patients with poor inhaler technique, to maximise lung drug deposition and reduce oropharyngeal deposition of fluticasone. The Seretide 125 strength (fluticasone 125 mcg/salmeterol 25 mcg per actuation) represents a medium-dose ICS/LABA combination — positioned between the Seretide 50 Evohaler (low-dose) and the Seretide 250 Accuhaler (high-dose dry powder inhaler).
Seretide 125 Evohaler is a prescription-only medication in the UK.
What Conditions Is Seretide 125 Evohaler Used For?
Seretide is indicated for:
The most common indication; treats bacterial cystitis in adults, including women and men.
regular maintenance treatment in patients whose asthma is not adequately controlled by ICS monotherapy at an equivalent dose; Seretide 125 is appropriate when a medium-dose ICS with LABA addition is clinically indicated
symptomatic maintenance treatment of patients with COPD (FEV1 <60% predicted) with a history of repeated exacerbations, as an alternative to ICS/LABA combinations where the specific fluticasone/salmeterol combination is preferred
salmeterol provides bronchodilation from approximately 15–20 minutes post-inhalation, though its slower onset compared to formoterol means it should be taken at least 30 minutes before exercise
Seretide is taken regularly every day regardless of symptom status. Salmeterol has a slow onset of action (15–20 minutes) and is not suitable for acute symptom relief. Patients prescribed Seretide must also have a separate short-acting reliever inhaler (salbutamol) for acute bronchospasm. Increasing use of the reliever inhaler is a warning sign of poor asthma control requiring urgent clinical review.
How Does Seretide 125 Evohaler Work?
Seretide's dual-component formulation addresses both the inflammatory and bronchomotor components of asthma and COPD:
Fluticasone propionate (ICS): Fluticasone propionate is a highly potent, topically active glucocorticoid with very high receptor affinity and extensive first-pass hepatic metabolism, resulting in minimal systemic bioavailability (<1% from the swallowed fraction). In the airways, fluticasone binds intracellular glucocorticoid receptors in bronchial epithelial cells, eosinophils, mast cells, and macrophages — suppressing the production of pro-inflammatory cytokines, adhesion molecules, and inflammatory mediators responsible for airway hyperresponsiveness, mucosal oedema, and mucus hypersecretion. Long-term fluticasone therapy reduces airway inflammation, hyperresponsiveness, and the risk of exacerbations.
Salmeterol (LABA): Salmeterol is a selective, long-acting beta-2 adrenergic agonist with a duration of action of approximately 12 hours. Its extended duration results from its highly lipophilic side chain anchoring the molecule in the airway smooth muscle cell membrane alongside the beta-2 receptor, allowing sustained receptor activation. Salmeterol relaxes airway smooth muscle, reduces mucosal oedema, and inhibits mast cell mediator release. The ICS and LABA components have complementary molecular synergy: fluticasone upregulates beta-2 receptor expression, maintaining salmeterol sensitivity; salmeterol enhances the anti-inflammatory efficacy of fluticasone.
Dosages & Administration
The correct dose depends on the type and severity of infection, age, weight, and kidney function. Always follow your clinician's instructions. The table below is for general reference only.
Administration Tips
Use a spacer device with the Evohaler. A spacer improves lung deposition of both ICS and LABA, reduces oropharyngeal fluticasone deposition (decreasing the risk of oral candidiasis and dysphonia), and is especially important for patients with impaired hand-breath coordination.
Shake the inhaler before each use. The pMDI suspension must be well mixed before actuation to ensure consistent drug delivery.
Breathe out gently, then actuate and inhale slowly and deeply simultaneously. Hold breath for 10 seconds. This is the critical difference from breath-actuated inhalers — coordination of pressing and inhaling is required.
Rinse mouth and gargle with water after every use — spit, do not swallow. This significantly reduces the risk of oral candidiasis and dysphonia from fluticasone deposition in the oropharynx.
Use regularly every 12 hours — do not stop using Seretide when feeling well; this is a controller medication that works continuously to prevent symptoms and exacerbations.
Side Effects of Seretide 125 Evohaler
Most side effects are mild and resolve on their own. Serious side effects are rare but require immediate medical attention.
- Oral candidiasis (thrush) --- largely preventable with consistent mouth rinsing after each dose; a spacer also reduces oropharyngeal deposition
- Dysphonia (hoarseness) --- from fluticasone deposition on the larynx
- Palpitations and tremor --- from salmeterol's beta-2 agonist activity; usually mild and transient
- Headache
- Throat irritation
- Paradoxical bronchospasm --- immediate worsening of airway obstruction after inhalation; stop and use a fast-acting bronchodilator
- Adrenal suppression --- with high-dose or prolonged ICS therapy; risk is greater with fluticasone than with budesonide at equivalent doses due to fluticasone's higher potency; relevant in patients on multiple ICS sources or those switching from oral corticosteroids
- Hypokalaemia --- with high-dose salmeterol; monitor potassium in patients on concurrent diuretics or theophylline
- Cardiovascular effects --- tachycardia, QT prolongation at high salmeterol doses
- Severe hypersensitivity reactions --- rare
Fluticasone propionate is significantly more potent than beclometasone or budesonide at equivalent nominal doses. Its superior airway anti-inflammatory activity is accompanied by a proportionally greater potential for HPA axis suppression at high doses or with prolonged use. Patients on high-dose fluticasone-containing inhalers should carry a steroid warning card and be counselled about stress dosing requirements during physiological challenges such as surgery or serious illness.
Drug Interactions
Always disclose all prescription drugs, over-the-counter medicines, vitamins, and supplements to your clinician or pharmacist before starting Seretide 125 Evohaler
Increase systemic fluticasone exposure significantly due to inhibition of first-pass metabolism; risk of systemic corticosteroid effects including adrenal suppression; avoid concurrent use where possible.
additive QT prolongation risk with high-dose salmeterol.
additive hypokalaemia risk and cardiovascular effects with high-dose salmeterol.
no clinically significant interaction.
Important Warnings
Seretide 125 Evohaler is a maintenance treatment only. Salmeterol's onset of action (15–20 minutes) makes it unsuitable for relief of acute bronchospasm. Patients must have a separate short-acting reliever (salbutamol) and must know when to seek emergency care.
Fluticasone's high potency means even small amounts deposited in the oropharynx can promote oral candidiasis and cause dysphonia. Rinsing and spitting after every dose is the single most effective preventive measure and should never be omitted.
Patients on high-dose fluticasone-containing inhalers should carry a steroid warning card. Clinicians should assess total ICS dose and advise on stress dosing needs for surgical and serious illness scenarios.
Using a spacer with the Evohaler substantially improves drug delivery to the lungs, reduces oropharyngeal deposition, and improves efficacy and tolerability. All patients prescribed a pMDI should be assessed for spacer use at initiation.
Speak to a Clinician About Treatment
Getting advice no longer means sitting in a waiting room. Through The GP Service, you can consult with a licensed clinician in minutes — from home, on your lunch break, or wherever works for you. If treatment is clinically appropriate, your clinician can issue a prescription during the consultation. A consultation does not guarantee a prescription.
The treatment you need, when you need it.
Seretide 125 Evohaler FAQs
A spacer is strongly recommended. It removes the need for perfect hand-breath coordination, dramatically improves lung deposition of both fluticasone and salmeterol, reduces oropharyngeal drug deposition (and therefore the risk of oral thrush and hoarse voice), and results in better disease control. If you do not currently use a spacer, ask your clinician or pharmacist to provide one and demonstrate correct use.
Fluticasone propionate is a very potent corticosteroid. Drug deposited in the mouth and throat — rather than reaching the lungs — can promote the growth of Candida fungus, causing oral thrush, and can cause hoarseness from corticosteroid effects on the larynx. Rinsing thoroughly with water and spitting (not swallowing) after every dose eliminates most of this deposited drug and very effectively prevents these complications.
Seretide 125 Evohaler is a pMDI delivering fluticasone 125 mcg and salmeterol 25 mcg per actuation (typically 2 puffs twice daily = fluticasone 500 mcg/day). Seretide 250 Accuhaler is a dry powder inhaler delivering fluticasone 250 mcg and salmeterol 50 mcg per blister (one inhalation twice daily = fluticasone 500 mcg/day). Both deliver the same total daily fluticasone dose at their standard prescribed frequencies. The choice between pMDI (Evohaler) and DPI (Accuhaler) is based on patient preference, inhaler technique capability, and environmental considerations (pMDIs have a higher carbon footprint).
No. Salmeterol takes 15–20 minutes to start working and is not appropriate for acute symptom relief. For acute bronchospasm, use your separate short-acting bronchodilator (salbutamol). If you do not have a reliever inhaler, this must be addressed with your clinician — every patient on Seretide should have a salbutamol inhaler available.
Yes. Seretide's benefit is continuous — it suppresses airway inflammation (fluticasone) and maintains bronchodilation (salmeterol) around the clock. Stopping when well removes this protection and frequently leads to deterioration of asthma control within days to weeks. Feeling well on Seretide is a sign that it is working, not that it is no longer needed.