Metered-dose inhalers

The convenience and apparent simplicity of the pressurised metered-dose inhalers (pMDIs) make them attractive.

The patient needs to coordinate inhalation and actuation of the MDI to ensure adequate topical delivery of the drug. Even with optimal technique, 90% of the drug is deposited in the oropharynx.

Less than optimal inhalation technique is seen in around 50% of pMDI users (2). Periodic checking of inhaler technique should be performed, particularly if there are problems with control.

If there are significant problems with technique, a spacer device or breath-actuated pMDI may be indicated (1).

References:

1. National Institute for Health and Clinical Excellence (NICE) 2008. Inhaled corticosteroids for the treatment of chronic asthma in adults and in children aged 12 years and over.
2. National Institute for Health and Clinical Excellence (NICE) 2002. Inhaler devices for routine treatment of chronic asthma in older children (aged 5 - 15 years).