Preliminary bronchodilator dose effect on aerosol-delivery through different nebulizers in noninvasively ventilated COPD patients.

This study aimed to evaluate the effect of a preliminary bronchodilator dose on the aerosol-d elivery by different nebulizers in noninvasively ventilated chronic obstructive pulmonary disease (COPD) patients. COPD patients were randomized to receive study doses of 800 µg beclomethasone dipropionate (BPD) nebulized by either a vibrating mesh nebulizer (VMN) or a jet nebulizer (JN) connected to MinimHal spacer device. On a different day, the nebulized dose of beclomethasone was given to each patient by the same aerosol generator with and without preceded two puffs (100 µg each) of salbutamol delivered by a pressurized-metered dose inhaler. Urinary BPD and its metabolites in 30 min post-inhalation samples and pooled up to 24 h post-inhalation were measured. On day 2, ex-vivo studies were performed with BPD collected on filters before reaching patients which were eluted from filters and analyzed to estimate the total emitted dose. The highest urinary excretion amounts of BPD and its metabolites 30 min and 24 h post-inhalation were identified with pMDI + VMN compared with other regimens( < 0.001). The amounts of BPD and its metabolites excreted 30 min post inhalation had approximately doubled with pMDI + JN compared with JN delivery ( < 0.05). No significant effect was found in the ex-vivo study results except between VMN and JN with a significant superiority of the VMN ( < 0.001). Using a preliminary bronchodilator dose before drug nebulization significantly increased the effective lung dose of the nebulized drug with both VMNs and JNs. However, adding a preliminary bronchodilator dose increased the 24 hr cumulative urinary amount of the drug representing higher systemic delivery of the drug, which in turn could result in higher systemic side effects.