Texas Tech University School of Medicine, El Paso, TX 79905, USA.
Curr Med Res Opin. 2010 Jun;26(6):1269-75. doi: 10.1185/03007991003745233.
To evaluate the efficacy of levocetirizine 5 mg once daily in reducing seasonal allergic rhinitis (SAR) symptoms in US adults.
This multicenter, randomized, double-blind, placebo-controlled, parallel-group study enrolled adults aged 18 to 65 years with SAR symptoms in the spring in the US. After a single-blind placebo run-in period, subjects received levocetirizine 5 mg or placebo once daily over 14 days. ClinicalTrials.gov registry no.: NCT00621959.
Primary efficacy variable was the Total 5-Symptom Score (T5SS). Secondary variables included Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), Work Productivity and Activity Impairment-Allergy Specific (WPAI-AS) questionnaire, and Epworth Sleepiness Scale (ESS). Safety assessments were based on adverse events (AEs).
The intent-to-treat population comprised 596 subjects (levocetirizine, n = 301; placebo, n = 295). Comparison of mean T5SS over the total treatment period showed a nonsignificant between-group difference (levocetirizine, 8.90 +/- 0.19; placebo, 9.04 +/- 0.19; adjusted mean difference, -0.14; p = 0.546). Levocetirizine showed numerical (mean RQLQ, WPAI-AS, ESS) and statistically superior differences (two domains within WPAI-AS) compared with placebo upon analysis of secondary efficacy variables. The incidence of treatment-emergent AEs was similar (levocetirizine, 23.9%; placebo, 24.4%). As the lack of efficacy was inconsistent with all previous levocetirizine studies, post hoc analyses were performed to assess the influence of pollen counts, geography, and other factors; however, no conclusive explanation could be identified.
In this study, levocetirizine 5 mg QD was well tolerated but failed to show significant efficacy compared with placebo in a US adult population with SAR. This finding is inconsistent with all previous studies with levocetirizine and in contrast to a concurrently run, similarly designed US study. It reflects the importance of conducting duplicate studies as there is always a small but real risk of false negative results in clinical studies, irrespective of the methodologic quality.
评估左西替利嗪 5 毫克每日 1 次给药在减轻美国成年人季节性变应性鼻炎（SAR）症状方面的疗效。
这项多中心、随机、双盲、安慰剂对照、平行组研究纳入了在美国春季出现 SAR 症状、年龄在 18 至 65 岁之间的成年人。在为期 14 天的单次盲法安慰剂导入期后，受试者接受左西替利嗪 5 毫克或安慰剂每日 1 次治疗。ClinicalTrials.gov 注册号：NCT00621959。
主要疗效变量是总 5 症状评分（T5SS）。次要变量包括鼻结膜炎生活质量问卷（RQLQ）、工作效率和活动障碍-过敏特异性（WPAI-AS）问卷以及 Epworth 嗜睡量表（ESS）。安全性评估基于不良事件（AE）。
意向治疗人群包括 596 例受试者（左西替利嗪组 n = 301；安慰剂组 n = 295）。整个治疗期间平均 T5SS 的比较显示组间无显著差异（左西替利嗪组 8.90 ± 0.19；安慰剂组 9.04 ± 0.19；调整后的平均差异 -0.14；p = 0.546）。与安慰剂相比，左西替利嗪在分析次要疗效变量时表现出数值（平均 RQLQ、WPAI-AS、ESS）和统计学上的优势差异（WPAI-AS 的两个域）。治疗中出现的不良事件发生率相似（左西替利嗪组 23.9%；安慰剂组 24.4%）。由于缺乏疗效与所有先前的左西替利嗪研究不一致，因此进行了事后分析以评估花粉计数、地理位置和其他因素的影响；然而，没有得出明确的解释。
在这项研究中，左西替利嗪 5 毫克 QD 耐受性良好，但与安慰剂相比，在美国 SAR 成年人群中未显示出显著疗效。这一发现与所有先前的左西替利嗪研究不一致，与同时进行的、设计类似的美国研究结果相反。这反映了重复研究的重要性，因为无论方法学质量如何，临床研究中总是存在小但真实的假阴性结果的风险。
