Day J H, Briscoe M, Widlitz M D
Department of Medicine, Queens University, Kingston, Ontario, Canada.
J Allergy Clin Immunol. 1998 May;101(5):638-45. doi: 10.1016/S0091-6749(98)70172-1.
Allergic rhinitis affects nearly one in 10 Americans. Cetirizine is a newer once-daily selective H1-antagonist. In traditional clinical trials, cetirizine has been shown to be safe and effective for the treatment of seasonal and perennial allergic rhinitis and chronic idiopathic urticaria.
To better characterize the efficacy and onset of action of cetirizine in a more controlled but clinically relevant setting, this agent was compared with loratadine and placebo in patients with symptomatic seasonal allergic rhinitis undergoing controlled pollen challenge in an environmental exposure unit (EEU).
This was a double-blind, randomized, parallel-group study. After screening, patients were exposed to ragweed pollen (primed) in the EEU (up to six exposures), and those with qualifying symptom scores were randomized to controlled pollen exposure (two periods of 5.5 to 6.5 hours over 2 days) and once-daily treatment with 10 mg cetirizine (n = 67), 10 mg loratadine (n = 67), or placebo (n = 68). The mean ragweed pollen level was 3480 +/- 350 grains/m3 (standard deviation). The primary efficacy variables were the total symptom complex (TSC) and the major symptom complex (MSC) scores. Symptoms were evaluated every half hour in the EEU throughout the study.
Cetirizine produced a 36.7% mean reduction in TSC scores overall versus 15.4% with loratadine and 12.0% with placebo (p < or = 0.01). Cetirizine also produced a 37.4% mean reduction in MSC scores overall versus 14.7% with loratadine and 6.7% with placebo (p < or = 0.01). Onset of action as assessed by reductions in TSC and MSC scores versus placebo was evident within 1 hour with cetirizine (p < or = 0.02) and 3 hours with loratadine (p < or = 0.03). The incidence of treatment-related side effects was similar among groups, with headache reported most commonly in each group.
Cetirizine is well tolerated and effective in reducing symptoms of seasonal allergic rhinitis in patients undergoing controlled pollen challenge.
过敏性鼻炎影响着近十分之一的美国人。西替利嗪是一种新型的每日一次服用的选择性H1拮抗剂。在传统的临床试验中，西替利嗪已被证明对治疗季节性和常年性过敏性鼻炎以及慢性特发性荨麻疹是安全有效的。
为了在更可控但临床相关的环境中更好地描述西替利嗪的疗效和起效情况，将该药物与氯雷他定和安慰剂在环境暴露单元（EEU）中接受受控花粉激发试验的有症状季节性过敏性鼻炎患者中进行比较。
这是一项双盲、随机、平行组研究。筛选后，患者在EEU中暴露于豚草花粉（预先致敏）（最多6次暴露），那些症状评分符合条件的患者被随机分配接受受控花粉暴露（2天内两个时间段，每次5.5至6.5小时），并每日一次服用10毫克西替利嗪（n = 67）、10毫克氯雷他定（n = 67）或安慰剂（n = 68）。豚草花粉的平均水平为3480±350粒/立方米（标准差）。主要疗效变量是总症状复合体（TSC）和主要症状复合体（MSC）评分。在整个研究过程中，在EEU中每半小时评估一次症状。
西替利嗪使TSC评分总体平均降低36.7%，而氯雷他定为15.4%，安慰剂为12.0%（p≤0.01）。西替利嗪还使MSC评分总体平均降低37.4%，而氯雷他定为14.7%，安慰剂为6.7%（p≤0.01）。以西替利嗪治疗后TSC和MSC评分相对于安慰剂的降低来评估，其起效在1小时内明显（p≤0.02），氯雷他定则在3小时内明显（p≤0.03）。各治疗组中与治疗相关的副作用发生率相似，每组中最常报告的是头痛。
在接受受控花粉激发试验的患者中，西替利嗪耐受性良好且能有效减轻季节性过敏性鼻炎的症状。
