商品名：Marquis
Antiprotozoal drug. Coccidiostat. Ponazuril (also known as toltrazuril sulfone) is a metabolite of the poultry antiprotozoal drug toltrazuril. Ponazuril is a triazine-based drug that acts to inhibit enzyme systems in protozoa and/or decreasing pyrimidine synthesis. It is specific for Apicomplexan organisms because the action attacks the apicoplast organelle in protozoa. It is specific in action as an antiprotozoal agent without affecting other organisms. It has high oral absorption in horses and a half-life of 4.5 days.
Toltrazuril, the parent drug, has been used for protozoa such as Isospora, Coccidia spp., Toxoplasma gondii, and Eimeria spp. Ponazuril has a long half-life in horses (>4 days), and concentrations in cerebrospinal fluid (CSF) are 3.5%-4% of serum concentrations but high enough to inhibit protozoa. Ponazuril is specifically approved for use as a treatment of equine protozoal myeloencephalitis (EPM), caused by Sarcocystis neurona. In clinical studies in horses with EPM, 62% of 101 horses were treated successfully with doses of 5 or 10 mg/kg for 28 days.
劑量數字暫停提供：VetPro 的劑量改依 DRUGAPI 藥物資料庫對外的內容，DRUGAPI 目前不提供可直接計算的劑量。下方列出 DRUGAPI 的審查結論與劑量審查引用的來源；計算機可手動輸入劑量換算。
Marquis 馬 EPM 為 loading／maintenance 多階段療程；犬貓方案則屬標示外且文獻不一致。exact product、物種、診斷、法域、調劑濃度、器具與多階段療程 gate 未齊前全面 fail closed。
DRUGAPI 劑量審查引用的獸醫官方標示（各標示只適用於其產品、物種與法域，不可互換）
依出現頻率分組；嚴重副作用獨立列出，臨床上需立即辨識。