RESUMO
Background: Complementary and alternative medicine, including Japanese traditional medicine (JTM), has been used for various allergic diseases, but the evidence is limited. Shoseiryuto (Xiao-Qing-Long-Tang), one of the representative JTM drugs, is frequently used to treat allergic rhinitis (AR). However, its efficacy for seasonal AR has not been fully established. Using an Environmental challenge chamber (ECC), we evaluated the therapeutic effects of shoseiryuto on AR induced by Japanese cedar pollen (JCP). Methods: A placebo-controlled double-blind crossover study with shoseiryuto was conducted using the ECC. The shoseiryuto or placebo was orally administered from 2 weeks before the exposure test. The pollen exposure test was conducted for 3 h, and the pollen concentration was set at 8000 pollen/m3. The primary endpoint of the study was the total nasal symptom score (TNSS) during pollen exposure. A physician certified by the Japanese Society of Oriental Medicine as a specialist checked each participant's "pattern", a comprehensive expression of signs obtained from individual patients' subjective symptoms and other personal findings. Blood samples collected just before the first pollen exposure were stimulated with cedar antigens and used for immunological studies. Results: The results of the 46 participants were analyzed, and no significant side effects were detected. There was no significant difference in TNSS during pollen exposure for 3 h in the ECC between the shoseiryuto and placebo groups. However, some symptoms were improved in the shoseiryuto group after leaving the ECC. There was no significant correlation between the "fluid retention pattern" and TNSS. In immunological studies, shoseiryuto did not inhibit Th2-type cytokine production and mRNA expression. Conclusions: Oral administration of shoseiryuto from 2 weeks before pollen exposure did not prevent or inhibit immediate symptoms of AR induced by JCP in the ECC. Further study is needed to reevaluate the shoseiryuto specific "pattern" in JTM.
RESUMO
BACKGROUND: No comparative study of antihistamines that differ in structural system has been conducted in allergic rhinitis. OBJECTIVE: This was a randomized, double-blind, crossover comparative study to verify the efficacy of antihistamines that differ in structural system. METHODS: A total of 50 patients with moderate or more severe Japanese cedar pollen-induced allergic rhinitis were randomized to receive either placebo, desloratadine 5 mg (a tricyclic), or levocetirizine 5 mg (a piperazine). One dose of the study drug was orally administered at 9 pm on the day before a pollen exposure test, which was performed for 3 h (9 a.m. to 12 p.m.) to assess symptoms in an environmental challenge chamber (ECC). Nasal and ocular symptoms were compared at an airborne pollen level of 8,000 grains/m3. The primary endpoint was mean total nasal symptom score (TNSS) from 120 to 180 min in the ECC. Subjects with a difference of ≥1 in TNSS between 2 drugs were extracted to the relevant drug-responsive group. RESULTS: The difference in TNSS from placebo was -2.42 (p < 0.0001) with levocetirizine and -1.66 (p < 0.01) with desloratadine, showing that both drugs were significantly more effective than placebo in controlling symptoms, but with no statistically significant difference between the 2 drugs. There were 12 subjects in the desloratadine-responsive group and 24 subjects in the levocetirizine-responsive group, with no contributor to response was detected. CONCLUSION: Levocetirizine tended to control nasal symptoms more effectively than desloratadine. However, the response to each antihistamine varied among individuals and the predictors to the response are unknown. CLINICAL TRIAL REGISTRATION NUMBER: UMIN ID: UMIN000029653.