Seretide

Seretide is a combination inhaler containing fluticasone propionate (an inhaled corticosteroid, ICS) and salmeterol (a long-acting beta-2 agonist, LABA).

This combination addresses both the underlying airway inflammation and bronchoconstriction characteristic of asthma and chronic obstructive pulmonary disease (COPD).

Fluticasone suppresses the inflammatory cascade in the airways, reducing mucosal oedema, mucus hypersecretion, and bronchial hyperresponsiveness.

Salmeterol provides sustained bronchodilation for approximately 12 hours by stimulating beta-2 adrenoceptors on airway smooth muscle.

BTS/SIGN and NICE asthma guidelines recommend the addition of a LABA to ICS (step 3) when low-dose ICS alone does not achieve adequate control.

Seretide is available as a metered-dose inhaler (Evohaler) and a dry powder inhaler (Accuhaler) in several strengths.

It is one of the most prescribed combination inhalers in the UK and has a well-established long-term safety and efficacy profile from over two decades of clinical use.

Seretide does not replace a reliever inhaler for acute bronchospasm.

Use Seretide regularly twice daily (morning and evening), approximately 12 hours apart, regardless of symptoms. This is a preventer/controller therapy and must be used consistently, not as a reliever.

For the Evohaler (MDI): shake well before each use, breathe out fully, place the mouthpiece between the lips, press the canister while breathing in slowly and deeply, hold breath for 10 seconds, then breathe out gently.

Use a spacer device if coordination is difficult.

For the Accuhaler (DPI): slide the lever to load a dose, breathe out away from the device, inhale forcefully and deeply through the mouthpiece, hold breath for 10 seconds.

Rinse your mouth with water after each use and spit out to reduce the risk of oral candidiasis and hoarseness from the corticosteroid component.

Asthma (adults): Seretide 100 Accuhaler (fluticasone 100 mcg/salmeterol 50 mcg) — one inhalation twice daily for mild-moderate asthma. Seretide 250 or 500 Accuhaler for moderate-severe disease.

Evohaler strengths: 50/25, 125/25, or 250/25 mcg — two puffs twice daily.

COPD: Seretide 500 Accuhaler — one inhalation twice daily (licensed for COPD with FEV1 <60% predicted and recurrent exacerbations).

Use the lowest strength that maintains asthma control. Step-down should be attempted after 3 months of good control. Do not exceed the prescribed dose.

No dose adjustment for elderly patients or mild-moderate renal/hepatic impairment. Potent CYP3A4 inhibitors (e.g.

ritonavir, ketoconazole) can increase systemic fluticasone exposure; co-administration should be avoided where possible.

Side effect data from SmPC and clinical trials.

Very common (≥1/10): Headache, nasopharyngitis.

Common (≥1/100 to <1/10): Oropharyngeal candidiasis (thrush), hoarseness/dysphonia, throat irritation, muscle cramps, tremor, palpitations, bruising.

Uncommon (≥1/1,000 to <1/100): Oral candidiasis, tachycardia, anxiety, sleep disturbance, behavioural changes (especially in children), hyperglycaemia, rash, cataracts, glaucoma.

Rare (≥1/10,000 to <1/1,000): Adrenal suppression (with prolonged high-dose ICS), growth retardation in children, osteoporosis, paradoxical bronchospasm, anaphylaxis, Churg-Strauss syndrome (in the context of corticosteroid dose reduction), hypokalaemia (more relevant with high LABA doses or concurrent beta-2 agonist overuse).

The risk of systemic corticosteroid effects increases with higher ICS doses and prolonged use. Mouth rinsing after inhalation significantly reduces candidiasis incidence.

Seretide is not for acute relief of bronchospasm; a short-acting reliever inhaler (e.g. salbutamol) must be available at all times.

Increasing use of reliever medication indicates deteriorating asthma control and necessitates clinical review.

Do not abruptly discontinue Seretide in patients transferred from oral corticosteroids, as adrenal insufficiency may occur. Monitor growth in children receiving prolonged ICS therapy.

The MHRA advises that patients on high-dose ICS should carry a steroid emergency card.

Concomitant use with potent CYP3A4 inhibitors (ritonavir, cobicistat, itraconazole, ketoconazole) can cause systemic corticosteroid effects including Cushing's syndrome and adrenal suppression; avoid concurrent use where possible.

Patients with active or quiescent pulmonary tuberculosis require specialist assessment before using ICS.

Seretide is contraindicated in patients with hypersensitivity to fluticasone propionate, salmeterol, or any excipient (lactose in the Accuhaler contains milk protein — contraindicated in severe milk allergy).

It should not be used as first-line therapy for asthma (ICS monotherapy should be tried first per NICE/BTS stepwise approach).

LABA monotherapy without ICS is contraindicated in asthma due to increased mortality risk observed in historical studies.