Department of Community Medicine, Bayero University of Kano, Kano, Nigeria.
PLoS Negl Trop Dis. 2010 Jul 27;4(7):e767. doi: 10.1371/journal.pntd.0000767.
In West Africa, envenoming by saw-scaled or carpet vipers (Echis ocellatus) causes great morbidity and mortality, but there is a crisis in supply of effective and affordable antivenom (ISRCTN01257358).
In a randomised, double-blind, controlled, non-inferiority trial, "EchiTAb Plus-ICP" (ET-Plus) equine antivenom made by Instituto Clodomiro Picado was compared to "EchiTAb G" (ET-G) ovine antivenom made by MicroPharm, which is the standard of care in Nigeria and was developed from the original EchiTAb-Fab introduced in 1998. Both are caprylic acid purified whole IgG antivenoms. ET-G is monospecific for Echis ocellatus antivenom (initial dose 1 vial) and ET-Plus is polyspecific for E. ocellatus, Naja nigricollis and Bitis arietans (initial dose 3 vials). Both had been screened by pre-clinical and preliminary clinical dose-finding and safety studies. Patients who presented with incoagulable blood, indicative of systemic envenoming by E. ocellatus, were recruited in Kaltungo, north-eastern Nigeria. Those eligible and consenting were randomly allocated with equal probability to receive ET-Plus or ET-G. The primary outcome was permanent restoration of blood coagulability 6 hours after the start of treatment, assessed by a simple whole blood clotting test repeated 6, 12, 18, 24 and 48 hr after treatment. Secondary (safety) outcomes were the incidences of anaphylactic, pyrogenic and late serum sickness-type antivenom reactions.
Initial doses permanently restored blood coagulability at 6 hours in 161/194 (83.0%) of ET-Plus and 156/206 (75.7%) of ET-G treated patients (Relative Risk [RR] 1.10 one-sided 95% CI lower limit 1.01; P = 0.05). ET-Plus caused early reactions on more occasions than did ET-G [50/194 (25.8%) and 39/206 (18.9%) respectively RR (1.36 one-sided 95% CI 1.86 upper limit; P = 0.06). These reactions were classified as severe in 21 (10.8%) and 11 (5.3%) of patients, respectively.
At these doses, ET-Plus was slightly more effective but ET-G was slightly safer. Both are recommended for treating E. ocellatus envenoming in Nigeria.
Current Controlled Trials ISRCTN01257358.
在西非，锯鳞蝰蛇（Echis ocellatus）或地毯蝰蛇的咬伤会导致严重的发病率和死亡率，但有效的、负担得起的抗蛇毒血清供应存在危机。
在一项随机、双盲、对照、非劣效性试验中，由 Clodomiro Picado 研究所生产的“EchiTAb Plus-ICP”（ET-Plus）马抗蛇毒血清与 MicroPharm 生产的“EchiTAb G”（ET-G）羊抗蛇毒血清进行了比较，ET-G 是尼日利亚标准治疗药物，由 1998 年引入的原始 EchiTAb-Fab 开发而来，均为己二酸纯化的全 IgG 抗蛇毒血清。ET-G 专门针对锯鳞蝰蛇抗蛇毒血清（初始剂量 1 瓶），ET-Plus 则针对锯鳞蝰蛇、黑曼巴蛇和非洲树蛇（初始剂量 3 瓶）。两者均经过临床前和初步临床剂量发现研究和安全性研究的筛选。在尼日利亚东北部的卡廷戈招募了出现不可凝固血液的患者，这表明已出现全身性锯鳞蝰蛇咬伤。符合条件并同意的患者以相等的概率随机分配接受 ET-Plus 或 ET-G 治疗。主要结局是在治疗开始后 6 小时内通过重复 6、12、18、24 和 48 小时后进行的简单全血凝血试验评估，永久性恢复凝血功能，次要（安全性）结局是过敏、发热和迟发性血清病型抗蛇毒血清反应的发生率。
ET-Plus 初始剂量在 194 名患者中有 161 名（83.0%），ET-G 在 206 名患者中有 156 名（75.7%）在 6 小时内永久性恢复凝血功能（相对风险 [RR] 1.10 单侧 95%CI 下限 1.01；P=0.05）。与 ET-G 相比，ET-Plus 引起早期反应的次数更多[分别为 50/194（25.8%）和 39/206（18.9%）]（RR（1.36 单侧 95%CI 1.86 上限；P=0.06）。这些反应在 21 名（10.8%）和 11 名（5.3%）患者中分别被分类为严重。
在这些剂量下，ET-Plus 略有效，但 ET-G 略安全。两者均推荐用于治疗尼日利亚的锯鳞蝰蛇咬伤。
当前对照试验 ISRCTN01257358。
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