Comparison of bronchodilatory properties of transdermal and inhaled long-acting beta 2-agonists.
BACKGROUND
Regular use of long-acting bronchodilators is recommended for symptomatic COPD patients. A transdermal type of beta 2-agonist, tulobuterol, was recently developed. This agent shows the pharmacokinetic property of a sustained serum concentration for 24h. However, little has been reported about the bronchodilatory properties of this agent.


OBJECTIVE
The aim of the present study was to compare the bronchodilatory action of transdermal beta 2-agonist tulobuterol with that of inhaled long-acting beta 2-agonist salmeterol.


METHODS
An open-label, randomized crossover study was performed. Eleven patients with stable COPD were enrolled in the study. Tulobuterol (2mg/day) or salmeterol (50 microg, twice daily) was administered in a randomized, crossover manner. Forced expiratory volume in 1s (FEV1), forced vital capacity (FVC) and inspiratory capacity (IC) were measured before administration, every 2h from 12 to 24h, and at 36 h after the initial administration.


RESULTS
Transdermal beta 2-agonist tulobuterol showed an improvement in FEV1, FVC and IC after dosing compared with those at baseline. Salmeterol also improved all parameters of FEV1, FVC and IC, and showed a greater improvement compared with the transdermal beta 2-agonist tulobuterol (p<0.05). The values of the area under the curve (AUC) of FEV1, FVC and IC during the administration of tulobuterol were 2.98+/-1.05, 1.81+/-0.98, 0.75+/-0.85 L h, respectively, and during the administration of salmeterol they were 6.39+/-1.12, 6.61+/-1.34, 4.28+/-0.91 L h, respectively.


CONCLUSIONS
The transdermal beta 2-agonist tulobuterol showed bronchodilatory action for at least 24h by once daily administration. However, its bronchodilatory potency was about three times less than that of the inhaled beta 2-agonist salmeterol.
Yamagata
T
T
Third Department of Internal Medicine, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama 641-8509, Japan.
Hirano
T
T
Sugiura
H
H
Yanagisawa
S
S
Ichikawa
T
T
Ueshima
K
K
Akamatsu
K
K
Nakanishi
M
M
Matsunaga
K
K
Minakata
Y
Y
Ichinose
M
M
D000279:Administration, Cutaneous; D000280:Administration, Inhalation; D058666:Adrenergic beta-2 Receptor Agonists; D000368:Aged; D000420:Albuterol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D018592:Cross-Over Studies; D003692:Delayed-Action Preparations; D005260:Female; D006801:Humans; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy*; D012129:Respiratory Function Tests; D000068299:Salmeterol Xinafoate; D013678:Technology, Pharmaceutical; D013726:Terbutaline / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use
D058666:Adrenergic beta-2 Receptor Agonists; D003692:Delayed-Action Preparations; C010809:tulobuterol; D000068299:Salmeterol Xinafoate; D013726:Terbutaline; D000420:Albuterol