摘要
Carboxylic ionophores, marketed worldwide as anticoccidial drugs for poultry and/or growth promotants for ruminants, are safe and effective at approved feed levels. However, toxic syndromes have resulted from overdosage, misuse and drug interactions. Ionophores facilitate transport of ions across biologic membranes. The anticoccidial and antibacterial activities of ionophores, such as monensin, result from increased transmembrane ion fluxes and dissipation of gradients. This mode of action reflects monensin’s innate properties, resulting in influx of Na+, efflux of H+ then K+ and intracellular alkalosis, followed by increased influx of Ca++. When homeostatic mechanisms are overwhelmed, the cell dies from osmotic shock. Thus, the usefulness of ionophores is based on selective toxicity to susceptible protozoa and bacteria and their margins of safety. The greatest risk of intoxication is upon initial exposure to ionophore-containing feed or supplement. Dose and time factors influence the severity and outcome of the toxic exposure. Clinical signs and lesions of ionophore toxicoses are not pathognomonic, but with a history of a feed-related problem, a presumptive diagnosis is warranted. Confirmatory diagnosis requires feed assays to determine amount(s) of the ionophore involved or concurrent use of an incompatible drug. There is no specific treatment; hence prevention of toxicity by proper use, avoidance of overdosing, and use only in approved species is recommended.
摘要译文
羧基离子载体在世界范围内被用作家禽的抗球虫药和/或反刍动物的生长促进剂，在批准的饲料水平下是安全有效的。但是，过量使用，滥用和药物相互作用都会导致中毒综合征。离子载体有助于离子跨生物膜的运输。离子载体（如莫能菌素）的抗球虫和抗菌活性来自跨膜离子通量的增加和梯度的消散。这种作用方式反映了莫能菌素的先天特性，导致Na + ，H + ，K + 流出，细胞内碱中毒涌入Ca ++ 的流入增加。当稳态机制不知所措时，细胞会因渗透压休克而死亡。因此，离子载体的用途是基于对易感染的原生动物和细菌的选择性毒性及其安全系数。中毒的最大风险是在最初接触含有离子载体的饲料或补充剂时。剂量和时间因素会影响中毒暴露的严重程度和结果。离子载体毒性糖的临床体征和损害不是致病的，但由于有与饲料有关的病史，因此有必要进行推定诊断。确诊需要进行饲料分析以确定参与或同时使用不相容药物的离子载体的量。没有特定的治疗方法。因此，建议通过正确使用防止毒性，避免过量使用，并仅在批准的物种中使用。
Meliton N.Novilla;. Ionophores. Veterinary Toxicology 003[M].US: ELSEVIER, 2018: 1073-1092