二氟沙星
Difloxacin
Difloxacin hydrochloride
別名: Dicural · A-56619 · Abbott-56619 · Difloxacin HCl
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
劑量為合格獸醫專業人員的臨床參考。請務必對照最新仿單及個別病患確認。
各物種劑量
🌎 NA — North America🌍 EU — Europe
狗
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Susceptible infections | 5-10 mg/kg | PO | q24h | 2-3 days beyond the cessation of clinical signs (maximum 30 days) | 🌎 NA |
- Susceptible infections: Administer preferably on an empty stomach, unless GI upset occurs.
馬
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Susceptible infections (MIC ≤ 0.25 micrograms/mL) | 7.5 mg/kg | PO | q24h | — | 🌎 NA |
- Susceptible infections (MIC ≤ 0.25 micrograms/mL): Administer non-fasted. Appears safe and adequately absorbed, but further investigation is warranted. Unknown if it should be avoided in young, growing horses.
劑量為合格獸醫專業人員的臨床參考。請務必對照最新仿單及個別病患確認。
概覽
二氟沙星（Difloxacin）是一種獸醫專用的氟喹諾酮類抗生素，主要用於治療犬隻的敏感性細菌感染。
主要臨床特徵：
- 保護腎臟： 與許多主要依賴腎臟清除的氟喹諾酮類藥物不同，二氟沙星經歷廣泛的肝膽排泄（超過80%由糞便排出）。這使其對於患有中度至重度腎衰竭的犬隻具有獨特優勢，較不易累積至毒性濃度。
- 抗菌譜： 對許多革蘭氏陰性及陽性桿菌和球菌（如克雷伯氏菌、葡萄球菌、大腸桿菌、腸桿菌、彎曲桿菌、變形桿菌和巴斯德桿菌）具有良好的療效。
- 局限性： 對大多數厭氧菌的活性較弱，且通常對腸球菌無效。部分綠膿桿菌菌株也可能具有抗藥性。
臨床要點： 氟喹諾酮類是濃度依賴型殺菌藥物。相對於最低抑菌濃度（MIC），最大化峰值濃度（Cmax）對於臨床療效及預防抗藥性至關重要。
作用機轉
Difloxacin is a concentration-dependent bactericidal agent.
- It actively enters the bacterial cell and targets DNA-gyrase (a type-II topoisomerase) and topoisomerase IV.
- Inhibition of these enzymes → prevents DNA supercoiling and uncoiling → halts DNA synthesis and transcription.
- The net result is rapid disruption of bacterial cell replication and subsequent cell death.
安全性與警告
禁忌症
- Hypersensitivity to difloxacin or other quinolones
- Immature dogs during the rapid growth phase (2-8 months in small/medium breeds; up to 18 months in large/giant breeds)
- Cats (relative contraindication due to nausea/vomiting and unknown ophthalmic/retinal safety)
- Food-producing animals (extra-label use prohibited by federal law)
不良反應
- Anorexia
- Vomiting
- Diarrhea
- Cartilage abnormalities (arthropathies) in growing animals
- CNS stimulation or seizures (rare)
- Facial erythema and edema (at high doses)
- Weight loss (at high doses)
注意事項
Use with caution in animals with known or suspected CNS disorders (e.g., seizure disorders), as fluoroquinolones have rarely been associated with CNS stimulation and seizures. Use with caution in patients with hepatic insufficiency, renal insufficiency, or dehydration. Safety in breeding or pregnant dogs has not been established.
藥物交互作用
May bind to difloxacin and prevent its absorption; separate doses by at least 2 hours.
Calcium content may decrease absorption; separate doses by at least 2 hours.
Unpredictable synergism may occur against some bacteria, particularly Pseudomonas aeruginosa.
May exacerbate nephrotoxicity and reduce the metabolism of systemic cyclosporine.
Severe hypoglycemia is possible.
Decreased difloxacin absorption; separate doses by at least 2 hours.
Increased methotrexate levels possible, resulting in toxicity.
May antagonize the antimicrobial activity of fluoroquinolones; concomitant use is not recommended.
Difloxacin may alter phenytoin blood levels.
May block tubular secretion and increase the blood level and half-life of difloxacin.
May inhibit absorption of difloxacin; separate doses by at least 2 hours.
Difloxacin may increase theophylline blood levels, potentially leading to toxicity.
Potential for increased anticoagulant effects.
監測
- Clinical efficacy (resolution of infection)
- Gastrointestinal signs (appetite, vomiting, diarrhea)
- CNS signs (especially in patients with a history of seizures)
藥物動力學
半衰期
吸收
Well absorbed orally in dogs (bioavailability >80%) with peak serum levels occurring about 3 hours post-dosing. In horses, oral bioavailability is approximately 70%.
分佈
Widely distributed. Volume of distribution (Vd) is 2.8-4.7 L/kg in dogs and ~1 L/kg in horses. Marginally bound to plasma proteins in dogs (16-52%).
代謝
Undergoes extensive hepatobiliary processing.
排除
Primarily eliminated via biliary excretion, with >80% of a dose eliminated in the feces. Only ~5% is excreted by the kidneys, though urine levels remain well above MICs for susceptible organisms for at least 24 hours.
過量
In dogs, doses up to 2.5X the maximum recommended dose (25 mg/kg) for 30 days did not cause overly significant adverse effects. Observed signs included facial erythema/edema, diarrhea, decreased appetite, and weight loss. Treatment should be supportive and symptomatic.
可用產品
劑型
- Oral tablets
- Oral suspension (compounded/investigational in horses)
獸醫用
- Difloxacin Oral Scored Tablets: 11.4 mg (single scored)
- Difloxacin Oral Scored Tablets: 45.4 mg (single scored)
- Difloxacin Oral Scored Tablets: 136 mg (double scored)
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
Commercially available tablets should be stored between 15-30°C (59-86°F) and protected from excessive heat.
飼主須知
二氟沙星是一種用於治療細菌感染的抗生素。
- 給藥方式： 最好在空腹時給予此藥物。但如果您的狗狗服藥後嘔吐或感到不適，未來的劑量可以與少量食物一起餵食。
- 重要交互作用： 請不要將此藥物與乳製品（如起司或優格）、制酸劑或含有鐵、鋅或鈣的補充劑同時餵食。這些物質會與藥物結合並阻止其吸收。請至少間隔 2 小時給藥。
- 完成療程： 即使您的寵物看起來已經完全康復，也請務必按照指示的完整時間給藥。提早停藥可能會導致感染復發且變得更難治療。
- 副作用： 如果您的寵物出現嚴重腹瀉、食慾不振、面部腫脹或任何異常的神經症狀（如發抖或癲癇），請立即聯繫您的獸醫師。
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