環丙沙星
**環丙沙星 (Ciprofloxacin)** 是一種第二代**氟喹諾酮類抗生素**，廣泛應用於人類醫學，在獸醫學中也常作為標示外使用。 * **抗菌譜**：廣效型，對許多革蘭氏陰性桿菌和球菌（包括綠膿桿菌、大腸桿菌、克雷伯氏菌屬）及部分革蘭氏陽性菌（如葡萄球菌屬，包含抗甲氧西林菌株）高度有效。對厭氧菌和多數鏈球菌的活性較弱。 * **藥代動力學特點**：在狗體內，其口服生物利用度顯著低於恩諾沙星 (enrofloxacin) 且較不穩定（僅約 40-50%，而恩諾沙星 >80%）。因此，通常不建議在犬隻中將其作為恩諾沙星的 1:1 口服替代品。 * **臨床應用**：通常在需要真正的靜脈注射 (IV) 氟喹諾酮製劑、針對特定細菌培養結果進行治療，或需要較大口服劑量規格時選用。
作用機制: Ciprofloxacin is a **bactericidal**, **concentration-dependent** antibiotic. * It enters the bacterial cell and inhibits two key type-II topoisomerase enzymes: **DNA gyrase** (primary target in gram-negative bacteria) and **Topoisomerase IV** (primary target in gram-positive bacteria). * Inhibition of these enzymes → prevents DNA supercoiling and relaxation → halts DNA replication and transcription → rapid bacterial cell death (within 20-30 minutes of exposure). * Exhibits a significant **post-antibiotic effect (PAE)**, meaning bacterial growth continues to be suppressed even after drug concentrations fall below the minimum inhibitory concentration (MIC).
各物種劑量
- Susceptible infections · 5-15 mg/kg PO q12h · PO · q12h · Avoid or reduce dosage in severe renal failure; avoid in young animals or pregnant/breeding animals.
- Ocular infections · 1 drop to affected eye · topical · q6h · Not specified · Standard therapy
- Severe ocular infections (intensive therapy) · 1 drop to affected eye · topical · q30-120mins · 1-2 days · For short-term intensive use
- Susceptible infections · 5-15 mg/kg PO twice daily · PO · twice daily
- Susceptible gram-negative infections · 20-40 mg/kg PO twice daily · PO · twice daily · Using ciprofloxacin 500 mg tablets. Crushed tablet goes into suspension well, but must be shaken well before administering.
- Susceptible gram-negative infections · 20 mg/kg PO q12h · PO · q12h · Using crushed tablets
- Susceptible gram-negative infections · 10-15 mg/kg PO q12h · PO · q12h · Using crushed tablets or suspend
- Susceptible infections (Ratites) · 3-6 mg/kg PO twice daily · PO · twice daily
- Susceptible infections (Rabbits) · 5-20 mg/kg PO q12h · PO · q12h
給藥途徑
禁忌症
- Hypersensitivity to fluoroquinolones
- Small and medium breed dogs 2-8 months of age (due to cartilage damage)
- Large and giant breed dogs during their rapid growth phase (past 8 months of age)
- Known hypersensitivity to ciprofloxacin or other fluoroquinolones
不良反應
- GI distress (vomiting, anorexia)
- Cartilage abnormalities in young, growing animals
- CNS stimulation (dizziness, seizures)
- Crystalluria
- Hypersensitivity reactions
- Local irritation after application
- Local burning and itching (reported in humans)
- Lid margin crusting (reported in humans)
- Hyperaemia (reported in humans)
- Taste disturbances (reported in humans)
- Corneal staining (reported in humans)
- Keratitis (reported in humans)
- Lid oedema (reported in humans)
- Lacrimation (reported in humans)
- Photophobia (reported in humans)
- Corneal infiltrates (reported in humans)
藥物相互作用
- Antacids/Dairy Products (Mg++, Al+++, Ca++) · May bind to ciprofloxacin and prevent its absorption; separate doses by at least 2 hours
- Antibiotics (aminoglycosides, 3rd-generation cephalosporins, extended-spectrum penicillins) · Synergism may occur against some bacteria (particularly Pseudomonas aeruginosa)
- Cyclosporine · May exacerbate nephrotoxicity and reduce the metabolism of cyclosporine
- Glyburide · Severe hypoglycemia possible
- Iron, Zinc (oral) · Decreased ciprofloxacin absorption; separate doses by at least two hours
- Methotrexate · Increased MTX levels possible with resultant toxicity
- Nitrofurantoin · May antagonize the antimicrobial activity of fluoroquinolones; concomitant use not recommended
- Phenytoin · May alter phenytoin levels
- Probenecid · Blocks tubular secretion of ciprofloxacin and may increase its blood level and half-life
- Quinidine · Increased risk for cardiotoxicity
- Sucralfate · May inhibit absorption of ciprofloxacin; separate doses by at least 2 hours
- Theophylline · May increase theophylline blood levels
監測
- Clinical efficacy
- Adverse effects (GI signs, CNS stimulation)
- Hydration status
- Clinical resolution of ocular infection
- Corneal healing (via fluorescein staining)
- Signs of local irritation or hypersensitivity
過量
Little specific information is available for ciprofloxacin overdosage in veterinary species. Overdoses may result in GI distress, CNS signs (tremors, seizures), or renal toxicity (crystalluria). Treatment should consist of supportive care, maintaining adequate hydration to prevent crystalluria, and gastric decontamination if ingestion was recent. See the enrofloxacin monograph for more extrapolated information.
VetSheet 藥物參考供持牌獸醫專業人員作臨床決策輔助之用,不能取代專業判斷或廠方最新藥品說明書。