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Canadian Respiratory Journal
Volume 12, Issue 1, Pages 26-28
Original Article

Effect of a Single Dose Montelukast Sodium on Methacholine Chloride PC20

Beth E Davis and Donald W Cockcroft

Division of Respiratory Medicine, Department of Medicine, University of Saskatchewan, Royal University Hospital, Saskatoon, Saskatchewan, Canada

Copyright © 2005 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


BACKGROUND: It is currently recommended that leukotriene modifiers (receptor antagonists and synthesis inhibitors) be withheld for a minimum of 24 h before direct bronchoprovocation testing, but there is little evidence to support this recommendation.

OBJECTIVE: To examine the effect of a single oral dose of montelukast sodium 10 mg on airway response to methacholine chloride-induced bronchoconstriction.

METHODS: A double-blind, placebo-controlled, randomized crossover trial was performed in 12 subjects with asthma whose methacholine chloride concentration causing a 20% decrease in the forced expiratory volume during the first second of exhalation (PC20) was 8 mg/mL or lower and a baseline forced expiratory volume during the first second of exhalation of 70% predicted or greater. Two-minute tidal breathing methacholine chloride inhalation challenges were performed 1 h and 25 h after both 10 mg montelukast sodium and identical-appearing placebo.

RESULTS: There were no significant differences in the methacholine chloride PC20 between active treatment and placebo at 1 h post-10 mg montelukast sodium (1.0 mg/mL versus 1.3 mg/mL; n=12; P=0.17, respectively) or at 25 h post-10 mg montelukast sodium (1.4 mg/mL versus 1.9 mg/mL; n=11; P=0.15, respectively).

CONCLUSION: A single dose of montelukast sodium did not affect methacholine chloride-induced bronchoconstriction measured after 1 h and 25 h.