Evaluation of Preliminary Bronchodilation Effect on Aerosol Delivery from a Dry Powder Inhaler for Patients with Chronic Obstructive Pulmonary Disease with Suboptimal Peak Inspiratory Flow Rate.

BACKGROUND

Suboptimal peak inspiratory flow rates (PIFR) are common in patients with chronic obstructive pulmonary disease (COPD), hindering effective medication dispersion and aerosol delivery. This study aimed to assess whether administering a preliminary bronchodilator dose via a pressurized metered-dose inhaler (pMDI) improves aerosol drug delivery via dry powder inhaler (DPI) in patients with COPD with suboptimal PIFR (< 60 L/min), compared with those with optimal PIFR (≥ 60 L/min).

METHODS

Overall, 24 patients with COPD were evaluated. PIFR was measured using the In-Check Dial© G16, dividing patients into optimal and suboptimal groups. All patients received a 200 µg dose of salbutamol via Diskus® DPI. Patients with COPD with suboptimal PIFR received two puffs (100 µg each) preceded by a preliminary salbutamol dose administered via pMDI®. Urine salbutamol levels (USAL30) and salbutamol that was eluted from filters (SALF) were measured after 30 min to assess lung deposition through high-performance liquid chromatography (HPLC).

RESULTS

Patients with COPD with suboptimal PIFR without a preliminary dose had significantly lower USAL30 than the optimal group (4.99% versus 6.18%, p = 0.013). A preliminary dose improved USAL30 in the suboptimal group but did not reach statistical significance (5.45% versus 4.99%, p = 0.071).

CONCLUSIONS

A significant difference in aerosol drug delivery was observed between optimal and suboptimal groups without a preliminary dose, suggesting that inhaler selection in patients with COPD may need to be individualized on the basis of inspiratory flow capability. Administering a preliminary dose of pMDI® before using a DPI minimally affects the suboptimal inhalation through DPI.