Clinical Category: Respiratory Health & Asthma Management
Medically Reviewed By: Pharma Direct UK Clinical Team
Last Updated: October 4, 2026 (Compliance: MHRA & GPhC Standards)For the millions of people in the UK living with asthma or Chronic Obstructive Pulmonary Disease (COPD), maintaining daily airway control is essential to prevent sudden breathlessness, coughing, and dangerous flare-ups.
When basic preventer therapies require optimization, prescribers frequently consider two of the most widely used inhalers in the NHS and private sectors: Fostair and Clenil Modulite. While both contain inhaled corticosteroids to target airway inflammation, their underlying formulations, active ingredients, and clinical roles differ significantly.Understanding the Active Ingredients
To manage asthma effectively, inhalers are categorized into Preventers (which suppress background inflammation) and Combination Inhalers (which combine anti-inflammatory agents with long-acting airway relaxants).
- Clenil Modulite (Single Preventer): Contains Beclometasone Dipropionate. It is a standalone inhaled corticosteroid (ICS) designed to be taken daily to reduce swelling and mucus production in the lungs over time. It does not provide immediate symptom relief during an acute attack.
- Fostair (Combination Inhaler): Combines Beclometasone Dipropionate (inhaled corticosteroid) with Formoterol Fumarate (a Long-Acting Beta-2 Agonist, or LABA). The steroid calms inflammation, while the LABA relaxes the smooth muscles surrounding the airways for up to 12 hours.
Head-to-Head Comparison
Feature Clenil Modulite Fostair Inhaler Class Single Preventer (ICS) Combination Preventer + Reliever (ICS + LABA) Active Ingredients Beclometasone Dipropionate Beclometasone Dipropionate + Formoterol Fumarate Particle Size Standard particle formulation Extra-fine particle formulation Primary Indication Mild to moderate persistent asthma Moderate to severe asthma / COPD MART Protocol Suitable No Yes (Fostair 100/6 can be used for Maintenance and Reliever Therapy) Available Devices Pressurised Metered Dose Inhaler (pMDI) pMDI (Pressurised) or NEXThaler (Dry Powder) Key Differentiating Factors
1. Extra-Fine Particle Technology
Unlike standard preventers, Fostair utilizes extra-fine particle engineering. Because the aerosol droplets are significantly smaller, the medication travels deeper into both the large airways and the microscopic peripheral airways of the lungs, delivering better coverage at lower comparative steroid doses.
2. The MART Protocol (Maintenance and Reliever Therapy)
Because the Formoterol component in Fostair relaxes airways rapidly (within 1–3 minutes) and lasts for 12 hours, specific strengths of Fostair (100/6) are licensed for MART. This allows patients to use their daily preventer inhaler as an immediate reliever when symptoms flare up, reducing the need for a separate blue Salbutamol inhaler. Clenil Modulite cannot be used as a reliever.
Do I need to rinse my mouth after using Clenil or Fostair?
Yes. Inhaled corticosteroids can leave microscopic residue in the oral cavity, which can lead to oral thrush (fungal infection) or hoarseness. Always rinse your mouth with water and spit it out after every dose.
Can I replace my blue reliever (Salbutamol) with Clenil Modulite?
No. Clenil Modulite is a slow-acting preventer and will not open constricted airways during an acute asthma attack. Always keep your fast-acting reliever inhaler with you unless your doctor has specifically prescribed a MART regimen with Fostair.
What is the difference between Fostair pMDI and Fostair NEXThaler?
Fostair pMDI is a traditional pressurized aerosol canister that requires press-and-breathe coordination (ideally used with a spacer device). The NEXThaler is a dry-powder inhaler triggered automatically when you inhale deeply through the mouthpiece.
How do I order asthma inhaler refills online in the UK?
You can complete an online medical assessment. At Pharma Direct UK, our registered prescribers evaluate your asthma control plan to safely supply and dispatch your prescribed inhalers.