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羅硝唑

Ronidazole

5-nitroimidazole compound

抗原蟲藥 / 硝基咪唑類抗生素PO貓

別名: Belga · Ridsol-S · Ronivet · Ronizol · Turbosol · Tricho Plus · Trichocure · Trichorex · ronidazolum

由 VetSheet 獸醫團隊審訂更新於 2026年4月5日本內容以實證獸醫文獻為本

30 mg/kg PO q24hPO· q24h· 14 days
— 🐈

劑量為持牌獸醫專業人員的臨床參考。請務必對照最新藥品說明書及個別病患確認。

各物種劑量

🌎 NA — North America🌍 EU — Europe

貓

適應症劑量途徑頻次療程地區
treatment of T. foetus infections30 mg/kg PO q24hPOq24h14 days🌎 NA
  • treatment of T. foetus infections: Likely to be most effective in resolving diarrhea and eradicating T. foetus infection. Must be given in capsule form due to bitter taste.

劑量為持牌獸醫專業人員的臨床參考。請務必對照最新藥品說明書及個別病患確認。

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概覽

​羅硝唑 (Ronidazole)​ 是一種強效的 ​5-硝基咪唑類 (5-nitroimidazole)​ 抗生素與抗原蟲藥物。雖然在結構上與甲硝唑 (metronidazole) 相似，但它對某些具抗藥性的原蟲展現出更佳的療效。

  • 主要在獸醫學中以仿單標示外使用 (off-label use) 的方式，用於根除貓的 胎兒三毛滴蟲 (Tritrichomonas foetus) 感染，這是造成貓咪慢性大腸性腹瀉的常見原因。
  • 也可用於鳥類醫學，治療非食用鳥類（如鴿子、雀鳥）的毛滴蟲感染。

​臨床要點​：由於其味道極度苦澀且對人類有潛在健康風險（疑似致癌物），必須謹慎地配製成完整的明膠膠囊。嚴禁使用於經濟動物（食用動物）。

作用機制

Ronidazole is a prodrug that requires activation by protozoal organelles called hydrogenosomes.

  • Inside the hydrogenosome, the drug is reduced → forms polar autotoxic anion radicals.
  • These highly reactive radicals bind to and disrupt protozoal DNA → inhibition of nucleic acid synthesis → cell death.

Note: While it shares this mechanism with metronidazole, ronidazole often retains activity against metronidazole-resistant T. foetus strains, though resistance to ronidazole has been documented.

安全性與警告

禁忌症

  • Hypersensitivity to ronidazole or other 5-nitroimidazoles (e.g., metronidazole)
  • Food-producing animals (FDA prohibited)
  • Pregnant or nursing cats (safety not established; use with extreme caution)

不良反應

  • Neurotoxicity (lethargy, anorexia, ataxia, nystagmus, seizures, behavior changes)
  • Gastrointestinal effects (anorexia, vomiting)
  • Carcinogenic potential (tumors in mice and rats)
  • Testicular toxicity (reported in dogs)

注意事項

Human Safety Warnings

  • Carcinogenic Potential: Demonstrated to be carcinogenic in mice. Humans should avoid contact with this compound or with animal waste from treated patients.
  • Compounding: Must be safely compounded using a biological safety cabinet to protect the compounder from drug exposure.
  • Administration: Wear disposable gloves when administering and when handling litter boxes.

Veterinary Precautions

  • Neurotoxicity: Reversible neurotoxicity can occur. Incidence appears higher at 50 mg/kg twice daily, but can occur at lower doses.
  • Regulatory: The FDA strictly prohibits this drug for use in food animals.

藥物相互作用

Alcohol

May induce a disulfiram-like reaction (nausea, vomiting, cramps)

Cimetidine

May decrease the metabolism of ronidazole and increase the likelihood of dose-related side effects

Ketoconazole

May decrease the metabolism of ronidazole and increase the likelihood of dose-related side effects

Cyclosporine

Ronidazole may increase the serum levels of cyclosporine

Tacrolimus

Ronidazole may increase the serum levels of tacrolimus

Fluorouracil

Ronidazole may increase the serum levels of fluorouracil and increase risk for toxicity

Lithium

Ronidazole may increase lithium serum levels and increase risk for lithium toxicity

Oxytetracycline

Reportedly may antagonize the therapeutic effects of metronidazole (and presumably ronidazole)

Phenobarbital

May increase the metabolism of ronidazole thereby decreasing blood levels

Rifampin

May increase the metabolism of ronidazole thereby decreasing blood levels

Phenytoin

May increase the metabolism of ronidazole thereby decreasing blood levels

Warfarin

May prolong INR/PT; avoid concurrent use if possible or intensify monitoring

監測

  • Clinical efficacy (diarrhea improvement)
  • Adverse effects (neurotoxicity, vomiting, anorexia)
  • PCR testing (to confirm infection; note that negative results after treatment do not conclusively prove eradication)

藥物動力學

半衰期

貓10 hours

吸收

Completely absorbed and bioavailable after oral dosing in cats.

分佈

Volume of distribution (steady state) is about 0.7 L/kg.

代謝

Hepatic metabolism suspected (similar to metronidazole).

排除

Clearance is approximately 0.8 mL/kg/min.

過量

Overdoses can cause severe neurotoxicity, hemorrhage, and death (as reported in society finches consuming ronidazole in drinking water). Cats receiving 50 mg/kg twice daily have a greater incidence of neurotoxicity.

Treatment:

  • Discontinue further therapy immediately.
  • Treat supportively.
  • Consider administering a GABA inhibitor, such as diazepam, to competitively inhibit GABA receptors in the CNS and control neurological signs.

可用產品

劑型

  • Compounded capsules (from 100% bulk powder)
  • 10% powder for drinking water (non-US veterinary product)

獸醫用

  • 10% ronidazole powder (non-US, for pigeons; unsuitable for cats)

各地核准狀態

暫無法規資料: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU

儲存與穩定性

Compounded capsules should be stored in child-resistant, tight containers protected from light. Until further stability studies can be performed, capsules should be stored in the freezer. Aqueous solutions are not very stable and should be prepared fresh daily.

飼主須知

​重要安全警告​：羅硝唑被認為是潛在的致癌物質。在處理藥物或清理貓砂盆時，​請務必戴上拋棄式手套​。

  • ​給藥方式​：請將膠囊整顆口服餵食。​切勿打開、壓碎或剝半​，因為藥粉極度苦澀且有暴露風險。
  • ​療程​：請嚴格按照獸醫師的指示給藥（通常為期14天）。請勿漏藥。
  • ​儲存方式​：請將膠囊保存在​冷凍庫​中，並使用防兒童開啟且避光的容器。
  • ​衛生清潔​：請將糞便排泄物裝入雙層塑膠袋中綁緊，再丟入一般垃圾桶。
  • ​何時應聯繫獸醫師​：如果您的寵物出現以下毒性反應跡象，請立即停藥並聯繫獸醫師：
    • 食慾不振或嘔吐
    • 精神沉鬱或行為改變
    • 走路不穩、絆倒或爬樓梯困難（共濟失調）
    • 眼球快速且不自主地來回跳動（眼球震顫）
    • 癲癇發作

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