A number of topical aspects of histamine or methacholine inhalation tests were discussed. First, the reporting of results as the dose delivered to the mouth by the method of aerosol generation and inhalation may allow better interpretation of results between laboratories. However, this requires investigation. Second, the histamine or methacholine dose-response curve differs in asthmatics with a moderate to severe increase in airway responsiveness from asthmatics with a mild increase in responsiveness or nonasthmatics. In the latter groups, the dose-response curve is positioned to the right and has a maximal response plateau. The disappearance of this limited maximal airway narrowing in asthmatics appears to be due to added abnormalities. Third, histamine or methacholine inhalation tests provide a sensitive and specific measure of the presence of variable airflow obstruction (asthma). They are useful to validate the diagnosis when symptoms are suggestive but spirometry is normal. The symptoms of asthma are not specific, and without objective confirmation the diagnosis is frequently misjudged even by the specialist. Finally, airway hyperresponsiveness to histamine or methacholine is not diagnostic of asthma when chronic airflow limitation is present; hyperresponsiveness to isocapnic hyperventilation may be more specific.

Keywords:
Airway responsiveness, Histamine, Methacholine, Diagnosis of asthma
This content is only available via PDF.
© 1986 S. Karger AG, Basel
1986
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.