Salmeterol protects against hyperventilation-induced bronchoconstriction over 12 hours.
To study the dose-response relationship of salmeterol for protection against a naturally occurring stimulus, isocapnic hyperventilation tests of cold air were done in 16 asthmatic patients. The subjects inhaled either 50 micrograms salmeterol, salbutamol 200 micrograms, or placebo in a double-blind, randomised, cross-over study. The FEV1 was measured prior to medication and the provocative ventilation (PV20) required to induce a 20% fall in FEV1 was calculated by linear interpolation from ventilation-response curves obtained 0.5, 4, 8, and 12 h after medication. Following salbutamol, the mean FEV1 were 4.11, 3.89, 3.58, and 3.55 l, with a significant difference from placebo up to 4 h. Following salmeterol, mean FEV1 values were 3.95, 4.10, 3.93, and 3.88 l, with a significant difference from placebo up to 12 h. The mean PV20FEV1 after salbutamol was 78.8, 58.5, 52.7, and 48.4 l.min-1, the 0.5 h value being significantly different from placebo. After salmeterol, the mean PV20FEV1 values were 84.6, 82.5, 67.8, and 65.8 l.min-1, with a significant difference from placebo up to 12 h. We conclude that, besides its long-lasting bronchodilating effect, salmeterol protects against hyperventilation-induced bronchoconstriction for at least 12 h.
Nowak
D
D
Grosshansdorf Hospital, Center for Pneumology and Thoracic Surgery, Hamburg, FRG.
Jörres
R
R
Rabe
K F
KF
Lüthke
M
M
Wiessmann
J
J
Magnussen
H
H
D000328:Adult; D000420:Albuterol / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology; D001985:Bronchial Provocation Tests; D016084:Bronchoconstriction / Q000187:drug effects*; D001993:Bronchodilator Agents / Q000494:pharmacology* / Q000627:therapeutic use; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006985:Hyperventilation; D008297:Male; D000068299:Salmeterol Xinafoate
D001993:Bronchodilator Agents; D000068299:Salmeterol Xinafoate; D000420:Albuterol