Respiratory medicine
-
Respiratory medicine · May 1994
Randomized Controlled Trial Comparative Study Clinical TrialReduced protection against exercise induced bronchoconstriction after chronic dosing with salmeterol.
The purpose of the present study was to assess the degree of protection of inhaled salmeterol against exercise-induced bronchoconstriction (EIB) after chronic compared with single dosing in patients with asthma. Twelve patients with exercise-induced asthma took part in a randomized double-blind crossover study to compare the duration of action of inhaled salmeterol 50 micrograms twice daily for 4 weeks with that of placebo. ⋯ The percentage fall in FEV1 after exercise challenge at 6 h was (first dose): placebo 34.8 +/- 4.9% vs. salmeterol 11.9 +/- 2.8% (P < 0.05); (4 weeks): placebo 32.9 +/- 5.3% vs. salmeterol 24.0 +/- 4.4% (NS). These results suggest that tachyphylaxis may develop to the functional antagonism of salmeterol against EIB.
-
Respiratory medicine · May 1994
Ethnic differences in normal spirometric lung function of Malaysian children.
Spirometric recordings of 1098 Malaysian children who were free of respiratory symptoms were examined by least square regression analysis of log-transformed lung function data. Ethnic differences were observed in FVC, FEV1, and FEF25-75 independent of father's education, exposure to passive smoking, wood stove, kerosene stove and mosquito repellents, family history of chest illness and history of allergy, after adjusting for standing height, age and sex. Exposure to kerosene stove was significantly associated with reduced FVC and FEV1 indicating that environmental factors may impair lung function in symptomless children. ⋯ Generally, Chinese children had higher FEV1, FVC and FEF25-75 than Malay and Indian children. Indian children consistently had the lowest lung function values. Since these ethnic differences were independent of environmental and other host factors, anthropometric variations could be an explanation.