Dose-response to salbutamol via a novel palm sized nebuliser (Aerodose Inhaler), conventional nebuliser (Pari LC Plus) and metered dose inhaler (Ventolin Evohaler) in moderate to severe asthmatics

AIMS: The Aerodose inhaler is a novel, palm-sized, breath actuated device which requires little patient coordination. This study compared the dose-response of salbutamol delivered by the Aerodose Inhaler (Aerogen Inc., Mountain View, USA) vs Pari LC Plus jet nebulizer (Pari LC Plus; Pari GmbH, Starnberg, Germany) and Ventolin Evohaler HFA pMDI (Evohaler; Allen & Hanburys [GlaxoSmithkline], Uxbridge, UK). METHODS: Twenty-two moderate to severe asthmatic patients, mean (s.d.) age: 44.7 (9.4), FEV(1): 58.1 (12.0), received 4 cumulative doubling doses of salbutamol in a randomised, investigator blind, balanced crossover design. Spirometry and systemic safety variables (heart rate, blood pressure, T wave amplitude, QTc interval and potassium) were measured at baseline and after each dose. RESULTS: Parallel regression analysis revealed that microgram relative potency ratios for the Aerodose Inhaler to be five times more efficient for FEV(1) than either the Pari LC Plus (0.202, 90% CI: 0.189-0.216) or the Evohaler (0.202, 90% CI: 0.189-0.216), while there was no difference between Pari LC Plus vs Evohaler. Similarly, Aerodose Inhaler vs. Pari LC Plus showed approximately five-fold greater potency for all systemic parameters, except blood pressure. As compared to the Evohaler, Aerodose Inhaler had equivalent potency for plasma potassium and T wave amplitude, but demonstrated greater potency for heart rate and QT(c) interval. CONCLUSIONS: This study has indicated therefore, that Aerodose Inhaler is approximately five times as efficient as the Pari LC Plus and Evohaler in relative lung delivery of salbutamol in moderate to severe asthmatics.