Evaluation of the efficacy and safety of olopatadine and fexofenadine compared with placebo in Japanese cedar pollinosis using an environmental exposure unit.

Abstract

BACKGROUND:

Second-generation oral H1-antihistamines have become a mainstay of treatment for the symptoms of seasonal allergic rhinitis; however, the effect of olopatadine has not been widely reported to date.

OBJECTIVES:

To evaluate the efficacy of 2 oral H1-antihistamines, olopatadine and fexofenadine, in the treatment of the nasal symptoms of Japanese cedar pollinosis and their possible side effects.

METHODS:

This was a randomized, double-blind, placebo-controlled, crossover study conducted in an environmental exposure unit (EEU). Twenty volunteers suffering from Japanese cedar pollinosis were randomly divided into 3 groups and exposed to cedar pollen in the EEU with oral administration of olopatadine hydrochloride (5 mg), fexofenadine hydrochloride (60 mg), or placebo 1 hour prior to pollen exposure. Nasal symptoms, activity impairment, and subjective sleepiness were self-assessed during the study period. Attention was measured using the digit cancellation test. The trial was repeated after 4 and 7 weeks.

RESULTS:

Compared with placebo, olopatadine significantly improved nasal symptoms and activity impairment during pollen exposure (P < .05). There was no significant relief of nasal discharge or nasal congestion with fexofenadine throughout the 5-hour exposure to cedar pollen. Furthermore, olopatadine significantly reduced nasal congestion during the first 2 hours, as well as sneezing and nasal discharge 4 hours after admission to the EEU compared with fexofenadine (P < .05). There was no significant difference in the effect on subjective sleepiness among the 3 groups, and all 3 agents had little effect on attention.

CONCLUSIONS:

These findings suggest that olopatadine is more effective than placebo and fexofenadine in improving nasal symptoms of Japanese cedar pollinosis.

• Authors: T Enomoto, H Q Lu, M Yin, T Sakoda, Y Dake, K Enomoto, T Ide, L Cheng
• Journal: Journal of investigational allergology & clinical immunology (J Investig Allergol Clin Immunol) Vol. 19 Issue 4 Pg. 299-305 ( 2009) ISSN: 1018-9068 [Print] Spain
• PMID: 19639726 (Publication Type: Journal Article, Randomized Controlled Trial)

Chemical References

• Allergens
• Dibenzoxepins
• Histamine H1 Antagonists, Non-Sedating
• Olopatadine Hydrochloride
• Terfenadine
• fexofenadine

Topics

• Adult
• Allergens (immunology)
• Cryptomeria (immunology)
• Dibenzoxepins (administration & dosage, adverse effects)
• Double-Blind Method
• Female
• Follow-Up Studies
• Histamine H1 Antagonists, Non-Sedating (administration & dosage, adverse effects)
• Humans
• Male
• Middle Aged
• Motor Activity (drug effects, immunology)
• Olopatadine Hydrochloride
• Pollen (immunology)
• Rhinitis, Allergic, Seasonal (drug therapy, immunology)
• Sleep (drug effects)
• Sneezing (drug effects)
• Terfenadine (administration & dosage, adverse effects, analogs & derivatives)
• Treatment Outcome