Cirak V Y, Aksit D, Cihan H, Gokbulut C
a Department of Parasitology, Faculty of Veterinary Medicine , Uludag University , Bursa , Turkey.
b Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine , Balikesir University , Balikesir , Turkey.
N Z Vet J. 2018 May;66(3):121-125. doi: 10.1080/00480169.2018.1426504. Epub 2018 Feb 7.
To determine the plasma disposition and concentrations of ivermectin (IVM) in eggs produced by laying hens following S/C, oral and I/V administration.
Twenty-four laying hens, aged 37 weeks and weighing 1.73 (SD 0.12) kg were allocated to three groups of eight birds. The injectable formulation of IVM was administered either orally, S/C, or I/V, at a dose of 0.2 mg/kg liveweight, following dilution (1:5, v/v) with propylene glycol. Heparinised blood samples were collected at various times between 0.25 hours and 20 days after drug administration. Eggs produced by hens were also collected daily throughout the study period. Samples of plasma and homogenised egg were analysed using HPLC.
Maximum concentrations of IVM in plasma and mean residence time of IVM were lower after oral (10.2 (SD 7.2) ng/mL and 0.38 (SD 0.14) days, respectively) than after S/C (82.9 (SD 12.4) ng/mL and 1.05 (SD 0.24) days, respectively) administration (p<0.01). The time to maximum concentration and elimination half-life were shorter following oral (0.14 (SD 0.04) and 0.23 (SD 0.11) days, respectively) than S/C (0.25 (SD 0.00) and 1.45 (SD 0.45) days, respectively) administration (p<0.01). IVM was first detected in eggs 2 days after treatment in all groups and was detected until 8 days after oral and I/V administration, and until 15 days after S/C administration. Peak concentrations of IVM were 15.7, 23.3 and 1.9 µg/kg, observed 2, 5 and 4 days after I/V, S/C and oral administration, respectively.
The low plasma bioavailability of IVM observed after oral administration in laying hens could result in lower efficacy or subtherapeutic plasma concentrations, which may promote the development of parasitic drug resistance. Due to high IVM residues in eggs compared to the maximum residue limits for other food-producing animal species, a withdrawal period should be necessary for eggs after IVM treatment in laying hens.
确定产蛋母鸡经皮下注射、口服和静脉注射伊维菌素（IVM）后，其在蛋中的血浆处置情况及浓度。
将24只37周龄、体重1.73（标准差0.12）千克的产蛋母鸡分为三组，每组8只。IVM注射制剂经丙二醇稀释（1:5，v/v）后，按0.2毫克/千克体重的剂量分别口服、皮下注射或静脉注射。给药后0.25小时至20天内不同时间采集肝素化血样。在整个研究期间，每天收集母鸡产的蛋。血浆和匀浆蛋样采用高效液相色谱法分析。
口服给药后血浆中IVM的最大浓度（分别为10.2（标准差7.2）纳克/毫升和0.38（标准差0.14）天）低于皮下注射给药后（分别为82.9（标准差12.4）纳克/毫升和1.05（标准差0.24）天）（p<0.01）。口服给药后达到最大浓度的时间和消除半衰期（分别为0.14（标准差0.04）和0.23（标准差0.11）天）短于皮下注射给药后（分别为0.25（标准差0.00）和1.45（标准差0.45）天）（p<0.01）。所有组在治疗后2天首次在蛋中检测到IVM，口服和静脉注射给药后8天内、皮下注射给药后15天内均能检测到。静脉注射、皮下注射和口服给药后分别在2、5和4天观察到IVM的峰值浓度，分别为15.7、23.3和1.9微克/千克。
产蛋母鸡口服IVM后血浆生物利用度低，可能导致疗效降低或血浆浓度低于治疗水平，这可能会促进寄生虫耐药性的产生。与其他产食用动物物种的最大残留限量相比，蛋中IVM残留量较高，因此产蛋母鸡经IVM治疗后，蛋需要有停药期。
