Pérez R, Cabezas I, Godoy C, Rubilar L, Muñoz L, Arboix M, Castells G, Alvinerie M
Laboratorio de Farmacología, Facultad Medicina Veterinaria, Universidad de Concepción, Chillán, Chile.
Vet J. 2002 Mar;163(2):161-7. doi: 10.1053/tvjl.2001.0624.
A study was undertaken in order to compare plasma disposition kinetic parameters of doramectin (DRM) and ivermectin (IVM) in horses after oral administration. Ten crossbreed adult horses, clinically healthy, weighing 380-470 kg body weight (bw) were selected for study. Faecal examinations were performed to determine faecal parasite egg counts. Horses were allocated to two groups of five animals to provide an even distribution considering the variables sex, body weight and faecal egg count. Group I, were treated with an oral paste formulation of IVM at 0.2 mg/kg b/w and Group II, were treated with an oral dose of 0.2 mg/kg bw of DRM prepared as paste from the injectable formulation for oral administration. Blood samples were collected by jugular puncture between 0 h and 75 days post-treatment. Plasma was separated and later solid phase extraction and derivatization samples were analysed by high performance liquid chromatography (HPLC); a computerised kinetic analysis was carried out. Data were compared using the Mann-Whitney U-test. The mean plasma concentrations of DRM and IVM after oral administration in horses were detected until 30 and 20 days, respectively. Both drugs showed similar patterns of absorption and no significant differences were found for peak concentration, the time to peak concentration, or for absorptive half-life. The terminal elimination half-life was significantly (P<0.05) longer in the DRM treated group than for the IVM treated group. The differences observed in the elimination half-life explain the longer mean residence time and high values of area under the concentration time curve for the group treated with DRM, which are 30% higher than those of the IVM group. Considering its pharmacokinetics, tolerance and anthelmintic efficacy, the oral administration of DRM, could be an alternative to IVM for the control of parasitic diseases of horses.
为比较多拉菌素（DRM）和伊维菌素（IVM）口服给药后在马体内的血浆处置动力学参数，开展了一项研究。选择10匹体重380 - 470千克（bw）的成年杂种临床健康马进行研究。进行粪便检查以确定粪便寄生虫卵计数。考虑到性别、体重和粪便卵计数等变量，将马分为两组，每组5只动物，以实现均匀分布。第一组用0.2毫克/千克体重的IVM口服糊剂制剂治疗，第二组用从注射用制剂制备的0.2毫克/千克体重的DRM口服剂量糊剂治疗。在治疗后0小时至75天之间通过颈静脉穿刺采集血样。分离血浆，随后通过高效液相色谱（HPLC）分析固相萃取和衍生化样品；进行计算机化动力学分析。使用曼 - 惠特尼U检验比较数据。马口服给药后DRM和IVM的平均血浆浓度分别在30天和20天内被检测到。两种药物显示出相似的吸收模式，在峰浓度、达峰时间或吸收半衰期方面未发现显著差异。DRM治疗组的终末消除半衰期明显（P<0.05）长于IVM治疗组。消除半衰期的差异解释了DRM治疗组较长的平均驻留时间和浓度 - 时间曲线下面积的高值，该组比IVM组高30%。考虑到其药代动力学、耐受性和驱虫效果，口服DRM可作为控制马寄生虫病的IVM替代品。
