[Therapy with nebulized beta2 agonists (procaterol) in asthmatic children: pulmonary function and plasma levels after inhalation].
BACKGROUND
Relationship between post administrative changes in plasma drug levels and bronchodilation remains unknown. In this study, we measured plasma levels of procaterol, a beta2-agonist, when being inhaled through nebulizers in children with bronchial asthma to examine relationship between improvement of pulmonary function and the plasma levels.


METHODS
Six asthmatic children with the mean age of 9.8 years, inhaled 0.3 ml of 0.01% procaterol solution through a nebulizer. We examined changes in pulmonary function and plasma procaterol levels before and after inhalation.


RESULTS
Procaterol was detected in the plasma 2 minutes after inhalation when it already rose to the maximum level, and kept the steady until showing a decline in 30 minutes. The measured highest value was 87.8+/-45.1 pg/ml. FEV 1.0 remarkably increased 2 minutes after inhalation and was maintained until 60 minutes after inhalation. Other lung function parameters also improved. There was no significant change in the heart rate, but serum potassium concentrations significantly dropped in all patients 60 minutes after inhalation.


CONCLUSIONS
Plasma procaterol levels promptly rose to the peak at 2 minutes after inhalation and decreased 30 minutes later. Improvement of pulmonary function started promptly at minutes after inhalation and it became a peak 60 minutes later.
Department of Pediatrics, Toho University Ohashi Medical Center. masa1114@med.toho-u.ac.jp
Masaru
M
Kishida
Hiroki
H
Nakazono
Rei
R
Kuroiwa
Hidenori
H
Dokai
Junko
J
Nakazato
Hiroaki
H
Nakamura
Itsuo
I
Suzuki
Noriaki
N
Shinomiya
D000280:Administration, Inhalation; D000293:Adolescent; D058666:Adrenergic beta-2 Receptor Agonists; D000318:Adrenergic beta-Agonists / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood*; D001249:Asthma / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D002648:Child; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008448:Maximal Expiratory Flow Rate; D009330:Nebulizers and Vaporizers; D011188:Potassium / Q000097:blood; D017265:Procaterol / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood*
D058666:Adrenergic beta-2 Receptor Agonists; D000318:Adrenergic beta-Agonists; D011188:Potassium; D017265:Procaterol