Tdgi. Tveld et al., EFFECT OF TOPICAL LEVOCABASTINE ON NASAL RESPONSE TO ALLERGEN CHALLENGE AND NASAL HYPERREACTIVITY IN PERENNIAL RHINITIS, Annals of allergy, asthma, & immunology, 75(3), 1995, pp. 261-266
Background: It has been demonstrated that some oral antihistamines red
uce nasal nonspecific reactivity and that topical levocabastine reduce
s cellular influx after nasal allergen challenge. This suggests that a
ntihistamines possess other properties besides classical H-1-receptor
antagonism. Objective: To evaluate the effect of 1 week's treatment wi
th topical levocabastine on the nasal clinical response, inflammatory
mediators, and nasal hyperreactivity. Methods: In a double-blind, plac
ebo-controlled, 2-period, 2-treatment, crossover study, 21 rhinitic pa
tients allergic to house dust mite participated. After each treatment
period patients were challenged with house dust mite extract. Symptom
scores and nasal lavages were collected for nine and one-half hours af
ter challenge. Allergen-induced nasal hyperreactivity was determined b
y nasal methacholine challenge 24 hours after allergen challenge. A na
sal histamine challenge was performed as well. Results: Patients showe
d only an immediate nasal response. Levocabastine significantly reduce
d the symptom score after 100 (P =.0063), 1000 (P =.0035), and 10,000
biological units (BU)/mL (P =.0013) of house dust mite extract. Albumi
n influx and tryptase release were not significantly reduced by levoca
bastine. No release of histamine and eosinophil cationic protein was s
een. Levocabastine did not reduce nasal response to methacholine. Acti
ve treatment significantly reduced histamine-induced nasal secretion (
P =.0009) and the number of sneezes (P =.0001). Conclusion: A signific
ant effect of levocabastine was shown on the immediate clinical respon
se to house dust mite and to histamine challenge only. Our findings su
ggest that levocabastine is an effective H-1-receptor antagonist witho
ut antiinflammatory properties.