inhalers

2 min read Updated 2026-03-16
Contents
inhaler therapy

Delivery of medication directly to the airways reduces systemic side effects and increases local concentration. Device selection and technique are as important as the medication itself. Most “uncontrolled” patients have poor technique rather than refractory disease.


device types

metered-dose inhalers (MDI)

  • Mechanism: Pressurised canister releases a measured dose of aerosolised medication.
  • Technique: Requires coordination between actuation and inhalation. Slow, deep breath over 3–5 seconds.
  • Spacer/VHC: Should be used with all MDIs. Eliminates coordination issues, reduces oropharyngeal deposition (thrush risk), and increases lung delivery.

dry powder inhalers (DPI)

  • Mechanism: Breath-actuated; medication is in a fine powder form.
  • Technique: Requires sufficient inspiratory flow (forceful, deep breath). Not suitable for very young children or those in acute distress.
  • Examples: Turbuhaler, Diskus, Ellipta, Handihaler.

soft mist inhalers (SMI)

  • Mechanism: Spring-loaded mechanism generates a slow-moving mist.
  • Technique: Easier coordination than MDI; slow, long breath. Mist lasts longer in the air.
  • Example: Respimat.

common errors by device

DeviceCommon errorSolution
MDIInhaling too fast or poor coordinationUse a spacer; slow down inhalation
DPIInhaling too slowlyForceful, deep “sharp” inhalation
SpacerMultiple puffs into spacer at onceOne puff at a time; 5–6 breaths per puff
AllNot holding breath at end10-second breath hold

inhaler technique checklist

  1. Prepare: Remove cap, shake (if MDI), prime (if first use or unused for > 7 days).
  2. Exhale: Breathe out fully, away from the device.
  3. Inhale:
    • MDI: Slow, steady breath while actuating.
    • DPI: Quick, forceful, deep breath.
  4. Hold: Hold breath for 10 seconds (or as long as comfortable).
  5. Repeat: Wait 30–60 seconds before second puff (if prescribed).
  6. Rinse: Rinse mouth after ICS use to prevent candidiasis.

medication classes

  • SABA: Salbutamol (Ventolin) — rescue only.
  • ICS: Budesonide, Fluticasone, Ciclesonide — foundation of asthma care.
  • LABA: Salmeterol, Formoterol (rapid onset), Vilanterol.
  • LAMA: Tiotropium, Umeclidinium, Glycopyrronium — cornerstone of COPD care.
  • Combinations: ICS-LABA (Advair, Symbicort, Breo), LAMA-LABA (Anoro, Inspiolto), Triple (Trelegy, Breztri).
Symbicort (Budesonide-Formoterol)

Unique because formoterol has a rapid onset (like SABA) but is long-acting. This allows it to be used as both maintenance and reliever (MART/SMART therapy).

Key references