Albuterol MDI: Classification and Delivery System
Yes, an albuterol metered-dose inhaler (MDI) is indeed an aerosol inhaler. The albuterol MDI delivers medication as a pressurized aerosol spray that contains the medication in suspension or solution form 1.
Albuterol MDI Characteristics
Albuterol MDI (90 mcg/puff) is classified as a short-acting beta2-agonist (SABA) that is delivered through an aerosol mechanism. According to national asthma guidelines, this delivery system has several important features:
- Delivers medication as a fine mist of particles suspended in propellant
- Contains 90 mcg of albuterol per actuation (puff)
- Recommended dosing for adults during acute exacerbations: 4-8 puffs every 20 minutes for 3 doses, then every 1-4 hours as needed 1
- Recommended dosing for children: 4-8 puffs every 20 minutes for 3 doses, then every 1-4 hours as needed 1
Clinical Efficacy of MDI vs. Other Delivery Systems
The MDI delivery system has been extensively studied and compared to other delivery methods:
- In mild-to-moderate asthma exacerbations, an MDI with a valved holding chamber (VHC) is as effective as nebulized therapy when used with appropriate administration technique and coaching 1
- For optimal efficacy, MDIs should be used with a spacer or valved holding chamber, especially in pediatric patients 2
- The aerosol delivery from an MDI can be affected by various factors including ventilator mode, humidity, and breathing pattern in mechanically ventilated patients 3
Practical Considerations for MDI Use
When using an albuterol MDI:
- Always use a spacer/valved holding chamber when possible to improve medication delivery
- Proper technique is crucial for effective medication delivery
- For children, ensure a proper seal between face mask and child's face when using a spacer
- Allow 6-8 breaths per actuation when using a spacer with pediatric patients 2
Common Pitfalls and Caveats
Poor technique: Improper MDI technique significantly reduces medication delivery. Common errors include not shaking the canister, improper timing of inhalation, and breathing too rapidly.
Spacer use: Failure to use a spacer/valved holding chamber can reduce medication delivery, especially in children and elderly patients.
Maintenance: Not cleaning the MDI mouthpiece regularly can lead to medication buildup and reduced drug delivery.
Dose tracking: Many patients fail to track remaining doses, leading to use of empty inhalers during exacerbations.
The aerosol delivery system of albuterol MDI makes it a convenient, portable, and effective option for asthma management when used correctly.