Dry powder inhalers: advantages and limitations

Area of Science:

• Respiratory Medicine
• Pharmacology

Background:

• Development of new inhaler devices driven by metered dose inhaler (MDI) usability issues and chlorofluorocarbon (CFC) bans.
• Dry powder inhalers (DPIs) generally offer improved ease of use and reduced irritant effects compared to MDIs.
• DPIs are associated with a lower incidence of poor inhalation technique development in patients over time.

Purpose of the Study:

• To compare the efficacy and patient preference of different multidose DPIs.
• To assess the critical inspiratory flow requirements for effective bronchodilator delivery from DPIs.
• To evaluate the suitability of DPIs for patients with severe acute asthma.

Main Methods:

• Comparative analysis of multidose DPIs against conventional MDIs.
• Assessment of bronchodilator efficacy and patient inhalation technique.
• Evaluation of peak inspiratory flow rates in patients with severe acute asthma using DPIs like Turbuhaler.

Main Results:

• Multidose DPIs demonstrate comparable bronchodilation to MDIs.
• While therapeutic efficacy between Diskhaler and Turbuhaler is similar, patient preference leans towards Turbuhaler.
• Most patients with severe acute asthma can generate sufficient inspiratory flow for effective bronchodilator inhalation from a Turbuhaler.

Conclusions:

• DPIs represent a viable alternative to MDIs, offering improved usability and comparable efficacy.
• Turbuhaler may be preferred by patients over Diskhaler, despite similar therapeutic outcomes.
• Adequate inspiratory flow is crucial for DPI effectiveness; most severe asthma patients can achieve this with Turbuhaler, though spacer use is a limitation for high-dose steroid inhalation.