Saumell Carlos, Lifschitz Adrián, Baroni Renato, Fusé Luis, Bistoletti Mariana, Sagües Federica, Bruno Santiago, Alvarez Gustavo, Lanusse Carlos, Alvarez Luis
Laboratorio de Parasitología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Facultad de Ciencias Veterinarias, UNCPBA, Campus Universitario, 7000 Tandil, Argentina.
Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Facultad de Ciencias Veterinarias, UNCPBA, Campus Universitario, 7000 Tandil, Argentina.
Vet Parasitol. 2017 Mar 15;236:62-67. doi: 10.1016/j.vetpar.2017.01.025. Epub 2017 Feb 4.
The goal of the current study was to evaluate the comparative efficacy of ivermectin (IVM) against small strongyles (cyathostomins) following its oral and intramuscular (IM) administration, in naturally parasitized horses. The parasitological data were complemented with the assessment of the plasma disposition kinetics of IVM. The trial included two different experiments. In experiment I, 40 horses naturally infected with small strongyles were randomly allocated into four experimental groups (n=10) and treated with IVM (0.2mg/kg) as follows: IVM oral paste, animals were orally treated with Eqvalan (IVM 1.87% paste, as the reference formulation) by the oral route; IVM oral solution, animals were orally treated with Remonta (IVM 2% solution, as a test formulation); IVM IM solution, animals were IM treated with the test product (Remonta IVM 2% solution); and control, animals were kept without treatment as untreated controls. In experiment II, 24 horses naturally parasitized with small strongyles were randomly allocated into the same four experimental groups (n=6) described for experiment I. Faecal samples were individually collected directly from the rectum of each horse prior (day -1) and at 7 and 15 (Experiment I) or 7, 15 and 21 (Experiment II) days after-treatment, to assess the eggs per gram (epg) counts and estimate the efficacy of the treatments. Additionally, the comparative plasma disposition kinetics of IVM in treated animals was assessed in experiment II. In both experiments, an excellent (100%) IVM efficacy was observed after its oral administration (test and reference formulations). However, the IM administration of IVM resulted in a low efficacy (36-64%). Similar IVM plasma concentration was observed after its oral administration as a paste or as a solution. The higher IVM plasma profiles observed after the IM administration accounted for an enhanced systemic availability. The improved IVM efficacy observed against adult cyathostomins after its oral administration can be explained by an enhanced drug exposure of the worms located at the lumen of the large intestine. These findings may have a direct impact on the practical use of macrocyclic lactones in horses.
本研究的目的是评估伊维菌素（IVM）在自然感染寄生虫的马匹中经口服和肌肉注射（IM）给药后对小型圆线虫（杯状线虫）的相对疗效。寄生虫学数据通过评估IVM的血浆处置动力学得到补充。该试验包括两个不同的实验。在实验I中，40匹自然感染小型圆线虫的马匹被随机分为四个实验组（n = 10），并按以下方式用IVM（0.2mg/kg）治疗：IVM口服糊剂组，动物通过口服途径用Eqvalan（1.87% IVM糊剂，作为参比制剂）进行口服治疗；IVM口服溶液组，动物用Remonta（2% IVM溶液，作为受试制剂）进行口服治疗；IVM肌肉注射溶液组，动物用受试产品（Remonta 2% IVM溶液）进行肌肉注射治疗；对照组，动物不进行治疗作为未治疗对照。在实验II中，24匹自然感染小型圆线虫的马匹被随机分为与实验I相同的四个实验组（n = 6）。在治疗前（第 -1天）以及治疗后7天和15天（实验I）或7天、15天和21天（实验II），直接从每匹马的直肠单独采集粪便样本，以评估每克粪便虫卵数（epg）并估计治疗效果。此外，在实验II中评估了IVM在受试动物中的相对血浆处置动力学。在两个实验中，IVM经口服给药（受试和参比制剂）后均观察到极佳（100%）的疗效。然而，IVM肌肉注射给药的疗效较低（36 - 64%）。IVM以糊剂或溶液形式口服给药后观察到相似的血浆浓度。肌肉注射给药后观察到的较高IVM血浆曲线表明全身可用性增强。IVM经口服给药后对成年杯状线虫观察到的疗效改善可归因于位于大肠肠腔的蠕虫药物暴露增加。这些发现可能对大环内酯类药物在马匹中的实际应用产生直接影响。
