The effect of stepping down combination therapy on airway hyperresponsiveness to mannitol.
BACKGROUND
Controversy exists about the safety of long acting beta2-agonist (LABA) treatment, in particular in children. Combination therapy with a LABA and an inhaled corticosteroid (ICS) is prescribed to children with moderate asthma and can be stepped down by withdrawal of the LABA when asthma is well controlled.


OBJECTIVE
To analyze the effect of stepping down from LABA/ICS combination therapy to monotherapy with the same dose of ICS on the airway response to mannitol in asthmatic children.


METHODS
17 children, aged 12-17 years, with clinically stable asthma, receiving combination therapy, were analyzed in this observational prospective open-label study. Children performed a mannitol challenge at baseline and 30±4 days after their medication was stepped down to ICS monotherapy. The changes in the provoking dose of mannitol to cause a 15% fall in FEV(1) (PD(15)), response-dose ratio and recovery time following a short acting beta2-agonist to ≥95% of baseline FEV(1) were assessed.


RESULTS
Mannitol PD(15) and response-dose ratio did not significantly change after stepping down. The recovery time following a short acting beta2-agonist to ≥95% of baseline FEV(1) was significantly shorter (p=0.01) after the withdrawal of the LABA.


CONCLUSIONS
In short-term follow-up, stepping down clinically stable asthmatic children from combination therapy to monotherapy with an ICS does not change airway hyperresponsiveness (AHR) to mannitol but does shorten recovery time to baseline lung function following a rescue short acting beta2-agonist.
Department of Pediatrics, Medisch Spectrum Twente, Haaksbergerstraat 55, Postbus 50.000, 7513 ER Enschede, The Netherlands. elinkersten@gmail.com
Elin T G
ET
Kersten
Jean M M
JM
Driessen
Eric J
EJ
Duiverman
Bernard J
BJ
Thio
D000280:Administration, Inhalation; D000293:Adolescent; D000318:Adrenergic beta-Agonists / Q000627:therapeutic use*; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use*; D001249:Asthma / Q000188:drug therapy* / Q000276:immunology; D002648:Child; D004334:Drug Administration Schedule; D004342:Drug Hypersensitivity / Q000188:drug therapy* / Q000276:immunology; D004359:Drug Therapy, Combination / Q000379:methods; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008353:Mannitol / Q000627:therapeutic use*; D011446:Prospective Studies
D000318:Adrenergic beta-Agonists; D018927:Anti-Asthmatic Agents; D008353:Mannitol