Effect of terfenadine on the response to exercise and cold air in asthma

Authors

  • Wolfram Wiebicke MD,

    1. Department of Pediatrics and Child Health, Section of Respirology, University of Manitoba, Winnipeg, Canada
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  • Aven Poynter MD,

    1. Department of Pediatrics and Child Health, Section of Respirology, University of Manitoba, Winnipeg, Canada
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  • Mark Montgomery MD,

    1. Department of Pediatrics and Child Health, Section of Respirology, University of Manitoba, Winnipeg, Canada
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  • Victor Chernick MD,

    1. Department of Pediatrics and Child Health, Section of Respirology, University of Manitoba, Winnipeg, Canada
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  • Dr Hans Pasterkamp MD

    Corresponding author
    1. Department of Pediatrics and Child Health, Section of Respirology, University of Manitoba, Winnipeg, Canada
    • Department of Pediatrics and Child Health, Section of Respirology, Rm 103–671 William Ave., Winnipeg, Manitoba R3E 0Z2, Canada
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  • This study was supported by Merrell Dow Pharmaceuticals Inc., Concord, Ontario, Canada, and the Children's Hospital of Winnipeg Research Foundation, Inc. W.W., A.P., and M.M. were Fellows of the Manitoba Lung Association. H.P. is a Scholar of the Manitoba Health Research Council.

  • Presented at the meeting of the Midwest Society for Pediatric Research, November 1987, Chicago, IL.

Abstract

To assess the role of histamine as a mediator in the response to exercise and isocapnic hyperventilation of cold air (IHCA) in asthma, we studied nine asthmatic subjects, age 13 to 25 years. All had exercise induced asthma (EIA) and positive responses to IHCA. Baseline lung function was measured before standardized challenges with histamine, exercise and IHCA. On separate days, these tests were repeated 3 h after a single oral dose of 120 mg terfenadine (TF). Histamine responsiveness decreased significantly, with a provocative concentration, producing a ± 20% fall in FEV1 (PC20), of 1.1 ± 0.8 mg/ml (mean ± SEM) before and 12.0 ± mg/ml after the antihistamine. EIA was significantly less after TF, with 53 ± 5% mean maximal falls in FEV1 from baseline before, and 29 ± 9% after treatment (P < 0.01, paired t-test). In contrast, the effect of TF on the response to IHCA was insignificant, with mean maximal falls of 45 ± 7% in FEV1 before, and 41 ± 7% after treatment. There was a correlation between PC20 and lowest FEV1 (% predicted) for EIA (r = 0.56, P < 0.05), but not for IHCA (r = 0.34, NS). This study indicates a role of histamine as a mediator in EIA but not in IHCA, supporting different mechanisms for both stimuli.

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