Université Pierre et Marie Curie Paris 6 and Assistance Publique-Hôpitaux de Paris, Paris, France.
N Engl J Med. 2010 Mar 11;362(10):896-905. doi: 10.1056/NEJMoa0905471.
Head-lice infestation is prevalent worldwide, especially in children 3 to 11 years old. Topical insecticides (i.e., pyrethroids and malathion) used as a lotion, applied twice at an interval of 7 to 11 days, are typically used for treatment. Resistance of lice to insecticides, particularly pyrethroids, results in treatment failure. The efficacy of alternative agents is controversial.
We conducted a multicenter, cluster-randomized, double-blind, double-dummy, controlled trial comparing oral ivermectin (at a dose of 400 microg per kilogram of body weight) with 0.5% malathion lotion, each given on days 1 and 8, for patients with live lice not eradicated by topical insecticide used 2 to 6 weeks before enrollment. The cluster was defined as the household. Infestation was confirmed and monitored by means of fine-toothed combing. Patients were at least 2 years of age and weighed at least 15 kg; all were treated at the study sites. The primary end point was the absence of head lice on day 15.
A total of 812 patients from 376 households were randomly assigned to receive either ivermectin or malathion. In the intention-to-treat population, 95.2% of patients receiving ivermectin were lice-free on day 15, as compared with 85.0% of those receiving malathion (absolute difference, 10.2 percentage points; 95% confidence interval [CI], 4.6 to 15.7; P<0.001). In the per-protocol population, 97.1% of patients in the ivermectin group were lice-free on day 15, as compared with 89.8% of those in the malathion group (absolute difference, 7.3 percentage points; 95% CI, 2.8 to 11.8; P=0.002). There were no significant differences in the frequencies of adverse events between the two treatment groups.
For difficult-to-treat head-lice infestation, oral ivermectin, given twice at a 7-day interval, had superior efficacy as compared with topical 0.5% malathion lotion, a finding that suggests that it could be an alternative treatment. (ClinicalTrials.gov number, NCT00819520.)
头虱感染在全世界都很普遍，尤其是 3 至 11 岁的儿童。通常使用作为洗剂的局部杀虫剂（如拟除虫菊酯和马拉硫磷），每 7 至 11 天使用两次，作为治疗方法。虱子对杀虫剂，尤其是拟除虫菊酯的抗药性导致治疗失败。替代药物的疗效存在争议。
我们进行了一项多中心、集群随机、双盲、双模拟、对照试验，比较了口服伊维菌素（剂量为 400μg/千克体重）与 0.5%马拉硫磷洗剂，两者均在登记前 2 至 6 周使用的局部杀虫剂未能根除活虱的第 1 天和第 8 天使用。集群定义为家庭。通过细齿梳子确认和监测感染情况。患者年龄至少 2 岁，体重至少 15 公斤；所有患者均在研究地点接受治疗。主要终点是第 15 天无头虱。
共有来自 376 户家庭的 812 名患者被随机分配接受伊维菌素或马拉硫磷治疗。在意向治疗人群中，接受伊维菌素治疗的患者中有 95.2%在第 15 天无虱，而接受马拉硫磷治疗的患者中有 85.0%（绝对差异，10.2 个百分点；95%置信区间[CI]，4.6 至 15.7；P<0.001）。在符合方案人群中，接受伊维菌素治疗的患者中有 97.1%在第 15 天无虱，而接受马拉硫磷治疗的患者中有 89.8%（绝对差异，7.3 个百分点；95%CI，2.8 至 11.8；P=0.002）。两组治疗的不良事件频率无显著差异。
对于难以治疗的头虱感染，间隔 7 天口服伊维菌素两次的疗效优于局部使用 0.5%马拉硫磷洗剂，这表明它可能是一种替代治疗方法。（临床试验.gov 编号，NCT00819520。）
