AMBROXOL IMPROVES THE BRONCHO-SPASMOLYTIC ACTIVITY OF CLENBUTEROL IN THE GUINEA-PIG

Citation
M. Pairet et al., AMBROXOL IMPROVES THE BRONCHO-SPASMOLYTIC ACTIVITY OF CLENBUTEROL IN THE GUINEA-PIG, Journal of Pharmacy and Pharmacology, 49(2), 1997, pp. 184-186
Citations number
17
Categorie Soggetti
Pharmacology & Pharmacy
ISSN journal
00223573
Volume
49
Issue
2
Year of publication
1997
Pages
184 - 186
Database
ISI
SICI code
0022-3573(1997)49:2<184:AITBAO>2.0.ZU;2-Y
Abstract
The effects of ambroxol on the spasmolytic action of clenbuterol were investigated on acetylcholine-induced bronchospasm in guinea-pigs. Amb roxol (50 mg kg(-1) day(-1)) or vehicle was administered orally for 14 days. Approximately 45 min after the final dose on day 14, the animal s were anaesthetized and the spasmolytic effects of clenbuterol (3, 6 or 12 mu g kg(-1) injected intravenously) were determined by use of ac etylcholine (40 mu g kg(-1) i.v.)-induced bronchoconstriction. For bot h vehicle- and ambroxol-treated animals, a positive linear relationshi p was observed between the log-dose of clenbuterol and the percent inh ibition of bronchospasm. The calculated ED25 of clenbuterol (i.e. the dose producing 25% inhibition of the acetylcholine-induced bronchospas m) was 3.98 mu g kg(-1) (3.29 to 4.82 mu g kg(-1), 95% confidence inte rval) in the presence of ambroxol and 5.81 mu g kg(-1) (4.98 to 6.79 m u g kg(-1)) in the absence of ambroxol. The linear regressions with or without ambroxol differed from each other (P < 0.001) but ran paralle l (covariance analysis), enabling us to calculate a relative potency, the value of which was 1.46 (1.16 to 1.84). These results demonstrate that the spasmolytic activity of clenbuterol is significantly improved in animals pretreated with ambroxol.