Get access

The bronchial response to mannitol is attenuated by a previous methacholine test: but not vice versa

Authors


Correspondence:
Simon Francis Thomsen, Department of Respiratory Medicine, Bispebjerg Hospital, Bispebjerg Bakke 23, DK-2400 Copenhagen NV, Denmark.
E-mail: sft@city.dk

Summary

Aim To examine the airway response to inhaled mannitol performed before or after a methacholine challenge test in a group of asthmatics with different levels of disease.

Methods A total of 48 asthmatics, 18–73 years of age, were included in the study. Two pairs of challenges were performed in a random order on two separate days geqslant R: gt-or-equal, slanted24 h apart: either with mannitol performed first on day one, followed geqslant R: gt-or-equal, slanted1 h by methacholine, and methacholine as the first on day two, followed geqslant R: gt-or-equal, slanted1 h by mannitol or vice versa. A questionnaire-based interview was performed and lung function, exhaled nitric oxide, skin prick test, and blood eosinophil count were measured.

Results A total of 44% of the asthmatics used inhaled corticosteroids and 48% were atopic. The airway response to mannitol was attenuated when mannitol was given after methacholine, compared with the response to mannitol when it was given first [log response dose ratio (RDR): 1.42 vs. 1.60 (P=0.004)], whereas the response to methacholine was unchanged in the opposite test order [log RDR: 0.81 vs. 0.96 (P=0.102)].

Conclusion Bronchial challenges with inhaled mannitol and methacholine may be performed on the same day but provocation with mannitol should be performed before methacholine.

Get access to the full text of this article

Ancillary