Study objective: Comparison of the bronchodilator
response to an albuterol novel dry powder inhaler (DPI) (Clickhaler[
CH]; ML Laboratories PLC; St. Albans, UK) activated at various
inspiratory flow rates and to an albuterol pressurized metered-dose
inhaler (pMDI) by patients with moderate to moderately severe stable
Design: Randomized, double-blind,
placebo-controlled comparison of the bronchodilator response to
albuterol DPI (200 μg) at inspiratory flow rates of approximately 15,
30, and 60 L/min in patients with stable asthma with demonstrated
reversibility to albuterol. Active (albuterol via pMDI inhaled at 30
L/min) and placebo controls were included.
Single center study at the chest/allergy unit of a teaching hospital in
Patients: Sixteen patients with moderate to
moderately severe stable asthma.
results: Efficacy end points were FEV1, FVC,
FEV1/FVC, maximum expiratory flow, and forced expiratory
flow between 25% and 75% of vital capacity. Safety end points
included heart rate, BP, and tremor. There was no significant
difference between the bronchodilator response to albuterol via the CH
at 15, 30, and 60 L/min inspiratory flow rate and, at all flow rates,
no significant difference was found comparing albuterol CH with the
pMDI. All of the techniques for delivering albuterol provided
significantly better bronchodilatation than placebo. Adverse events
were minimal and did not differ between CH and pMDI or between the
various flow rates inhaled through the CH.
A novel passive albuterol DPI (CH) provides a similar bronchodilator
response at 15, 30, and 60 L/min inspiratory flow rates compared with a
pMDI used optimally.
Abbreviations: CH = Clickhaler; DPI = dry powder
inhaler; FEF25–75 = forced expired flow between 25% and
75% of vital capacity; MDI = metered-dose inhaler; MEF = maximum
expiratory flow; pMDI = pressurized metered-dose inhaler