ジクラズリル
**ジクラズリル (Diclazuril)** は、トリアジン（ベンゼンアセトニトリル）系に属する強力で広域スペクトルを持つ抗原虫薬です。 主な臨床応用： - **馬**：*Sarcocystis neurona* による馬原虫性脊髄脳炎（EPM）の治療薬としてFDAに承認されています。 - **家畜および家禽**：ブロイラー、子牛、子羊の抗コクシジウム薬として広く使用されています。 - **小動物**：犬や猫の難治性コクシジウム症、ネオスポラ（*Neospora caninum*）、トキソプラズマ（*Toxoplasma*）感染症の治療に適用外使用されます。 > **臨床のポイント**：EPMにおける原虫感染の排除には極めて有効ですが、寄生虫の中枢神経系への移行によってすでに生じた神経損傷を回復させることはできません。
作用機序: Diclazuril specifically targets the **apicoplast** (a plastid-like organelle) found uniquely in the *Apicomplexa* phylum (which includes *Sarcocystis*, *Toxoplasma*, and *Eimeria*). - **Mechanism**: It disrupts essential metabolic pathways within the apicoplast (likely involving lipid and heme biosynthesis) → halts intracellular schizogony and gametogony → **parasiticidal** effect. - **Potency**: It is highly potent, with *in vitro* concentrations required to inhibit 95% of *S. neurona* being exceptionally low (~1 ng/mL).
動物種別の用量
- Therapeutic use (lambs) · 1 mg/kg (1 mL of the 2.5mg/mL suspension per 2.5 kg bodyweight) PO once · PO · once · Recommended to treat all lambs in flock.
- Preventative use (lambs) · 1 mg/kg PO · PO · once · Administer at about 4-6 weeks of age at the time that coccidiosis can normally be expected. Under high infection pressure, a second treatment may be indicated about 3 weeks after the first dosing.
- Coccidiosis · 25 mg/kg PO once · PO · once
- Coccidiosis in kittens · 1 mL (2.5 mg) PO of the sheep solution per 4 kg body mass · PO · once
- Isospora spp. infections · 25 mg/kg PO once · PO · once
- As an aid to control coccidiosis (calves) · 1 mg/kg (1 mL of the 2.5 mg/mL suspension per 2.5 kg bodyweight) PO as a single dose · PO · once · Administer 14 days after moving into a potentially high risk environment. Recommended to treat all calves in pen.
- Treatment of equine protozoal myeloencephalitis (S. neurona) · Top dress at the rate of 1 mg/kg bodyweight · PO · q24h · 28 days · Using the oral pellets and the provided cup. If horse's bodyweight is in between two graduations on the dosing cup, fill the cup to the higher of the two marks.
投与経路
禁忌
- Hypersensitivity to diclazuril
- Safe use in horses used for breeding, during pregnancy, or in lactation has not been evaluated
有害事象
- Severe diarrhea (rarely, in highly susceptible lambs)
モニタリング
- Clinical efficacy (neurologic exams)
過量投与
Limited information is available, but the drug appears to have a large safety margin in animals. Normal horses dosed up to 50 mg/kg/day (50X) for 42 days developed only marginal effects (decreased weight gain, increased creatinine, BUN). Doses of up to 60X in lambs and calves did not cause any demonstrable side effects.
VetSheet の薬剤リファレンスは、獣医療従事者向けの臨床意思決定支援を目的としており、専門的判断やメーカーの最新添付文書に代わるものではありません。