Protective effect of montelukast on lower and upper respiratory tract responses to short-term cat allergen exposure.
BACKGROUND
Challenge with short-term exposure to airborne cat allergen in sensitized patients produces pulmonary function changes and rhinitis symptoms.


OBJECTIVE
To determine the benefit of montelukast, 10 mg, for patients with concomitant asthma and allergic rhinitis as demonstrated by protection against both lower and upper airway responses to cat allergen challenge.


METHODS
This randomized, crossover study treated patients with montelukast vs placebo during two 2-week, double-blind treatment periods, separated by a 1-week washout period. After each treatment period, patients underwent a 60-minute or less exposure to high levels of airborne cat allergen. Lower and upper airway responses were measured by spirometry and symptom scores.


RESULTS
Of 52 patients with data from both treatment arms, 79% of patients taking montelukast and 67% taking placebo were exposed to the full 60-minute allergen challenge. Montelukast provided significant (P < or = .001) protection against allergen challenge in the lower airway coprimary end point of area under the curve during challenge (AUC0-60min) for percentage decrease in forced expiratory volume in 1 second: mean of 10.5% per hour and 14.7% per hour for montelukast and placebo, respectively. Although the effect on the overall nasal symptoms score (NSS) coprimary end point of AUC0-60min was not statistically significance (P = .12), nasal congestion during the challenge and NSS during recovery showed statistically significant (P = .048) protection by montelukast. Additional analyses of simultaneous lower and upper airway responses showed that more patients taking montelukast (22, 43%) vs placebo (13, 26%) were protected from both asthma and rhinitis (P = .02), with an odds ratio of 2.24 (95% CI, 1.16-4.32) in favor of montelukast.


CONCLUSIONS
Montelukast has a protective effect against both lower and upper airway responses during exposure to high levels of cat allergen.
Perry
Tamara T
TT
Division of Allergy and Immunology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
Corren
Jonathan
J
Philip
George
G
Kim
Eric H
EH
Conover-Walker
Mary Kay
MK
Malice
Marie-Pierre
MP
Massaad
Rachid
R
Dass
S Balachandra
SB
Reiss
Theodore F
TF
Wood
Robert A
RA
D000085:Acetates / Q000494:pharmacology*; D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000276:immunology*; D000818:Animals; D019540:Area Under Curve; D001249:Asthma / Q000276:immunology*; D002415:Cats / Q000276:immunology*; D018592:Cross-Over Studies; D003521:Cyclopropanes; D004311:Double-Blind Method; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D006967:Hypersensitivity / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D011804:Quinolines / Q000494:pharmacology*; D012137:Respiratory System / Q000276:immunology*; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology*; D013440:Sulfides
D000085:Acetates; D000485:Allergens; D003521:Cyclopropanes; D011804:Quinolines; D013440:Sulfides; C093875:montelukast