Optimal particle size for beta 2 agonist and anticholinergic aerosols in patients with severe airflow obstruction.
BACKGROUND
The optimal particle size of a beta 2 agonist or anticholinergic aerosol in patients with severe airflow obstruction is unknown.


METHODS
Seven stable patients with a mean forced expiratory volume in one second (FEV1) of 37.9% of the predicted value inhaled three types of monodisperse salbutamol and ipratropium bromide aerosols with particle sizes of 1.5 microns, 2.8 microns, and 5 microns, respectively, and a placebo aerosol. The volunteers inhaled 20 micrograms salbutamol and 8 micrograms ipratropium bromide, after which lung function changes were determined and analysed with repeated measurements analysis of variance (ANOVA).


RESULTS
Greater improvements in FEV1, specific airway conductance (sGaw) and maximum expiratory flow at 75%/50% of the forced vital capacity (MEF75/50) were induced by the 2.8 microns aerosol than by the other particle sizes.


CONCLUSIONS
In patients with severe airflow obstruction the particle size of choice for a beta 2 agonist or anticholinergic aerosol should be approximately 3 microns.
Zanen
P
P
Department of Pulmonary Diseases, University Hospital Utrecht, The Netherlands.
Go
L T
LT
Lammers
J W
JW
D000318:Adrenergic beta-Agonists / Q000008:administration & dosage*; D000336:Aerosols; D000403:Airway Resistance; D000420:Albuterol / Q000008:administration & dosage*; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D009241:Ipratropium / Q000008:administration & dosage*; D008173:Lung Diseases, Obstructive / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010316:Particle Size; D014797:Vital Capacity
D000318:Adrenergic beta-Agonists; D000336:Aerosols; D001993:Bronchodilator Agents; D009241:Ipratropium; D000420:Albuterol