馬波沙星
**馬波沙星 (Marbofloxacin)** 是一種合成的廣效性**氟喹諾酮類抗生素**，主要用於獸醫學。它對革蘭氏陰性菌和革蘭氏陽性菌均表現出**濃度依賴性殺菌活性**及顯著的**抗生素後效應 (PAE)**。它在細菌複製的靜止期和生長期均具有活性。 * **抗菌譜**：對多種革蘭氏陰性桿菌和球菌（如綠膿桿菌、大腸桿菌、克雷伯氏菌、腸桿菌、變形桿菌、沙門氏菌）以及部分革蘭氏陽性菌（如葡萄球菌，包含產青黴素酶菌株）高度有效。 * **臨床要點**：與其他氟喹諾酮類藥物一樣，馬波沙星對大多數厭氧菌的活性較弱，對鏈球菌的療效不一或較差。不建議用於治療厭氧菌或鏈球菌感染。 * **抗藥性**：主要透過染色體突變產生（特別是在綠膿桿菌、克雷伯氏菌和腸球菌中）；質體介導的抗藥性極為罕見。
作用機制: Marbofloxacin exerts its bactericidal effect by targeting key bacterial enzymes involved in DNA replication and transcription: * Inhibits **DNA-gyrase** (topoisomerase II) → prevents DNA supercoiling. * Inhibits **Topoisomerase IV** → prevents separation of interlinked daughter DNA molecules. * **Result**: Disruption of DNA replication, transcription, and repair → rapid bacterial cell death (typically within 20-30 minutes of exposure).
各物種劑量
- For susceptible infections (urinary tract, skin and soft tissue) · 2.75-5.5 mg/kg PO once daily · PO · q24h · Give for 2-3 days beyond cessation of clinical signs (skin/soft tissue); at least 10 days (urinary tract). Max 30 days. · If no improvement noted after 5 days, reevaluate diagnosis.
- First-line treatment for feline tuberculosis or non-tuberculous mycobacteria (NTM) · 2 mg/kg PO once daily · PO · q24h · Pending definitive diagnosis. Not effective against MAC infection.
- For hemoplasmosis · 2.75 mg/kg PO once daily (q24h) · PO · q24h
- Susceptible bacterial infections · 2 mg/kg · IV/SC/PO · q24h · Not specified · Do not use 20 mg or 80 mg tablets. May allow clearance of Mycoplasma haemofelis in persistently infected cats.
- Susceptible infections · 10 mg/kg PO at least every 48 hours · PO · q48h · Study done in Ball pythons (Python regius). Further studies required to determine effective doses and toxicity.
- For susceptible infections (urinary tract, skin and soft tissue) · 2.75-5.5 mg/kg PO once daily · PO · q24h · Give for 2-3 days beyond cessation of clinical signs (skin/soft tissue); at least 10 days (urinary tract). Max 30 days. · If no improvement noted after 5 days, reevaluate diagnosis.
- For susceptible Pseudomonas otitis · 5.5 mg/kg PO once daily · PO · q24h · Dose at the high end of the flexible dosing label for severe/chronic cases or when topical therapy is not possible.
給藥途徑
禁忌症
- Hypersensitivity to fluoroquinolones
- Small and medium breed dogs up to 8 months of age
- Large breed dogs up to 12 months of age
- Giant breed dogs up to 18 months of age
- Cats under 12 months of age
- Food-producing animals (FDA prohibited)
- Cats (do not use 20 mg and 80 mg tablets)
- Dogs < 12 months of age
- Giant-breed dogs < 18 months of age
- Cats < 16 weeks of age
不良反應
- Gastrointestinal distress (vomiting, anorexia, soft stools, diarrhea)
- Decreased activity/lethargy
- Cartilage abnormalities in young, growing animals
- Elevated hepatic enzymes (rare)
- Ataxia, seizures, depression, nervousness (rare)
- Hypersensitivity reactions (rare)
- Crystalluria (rare)
- Potential ocular toxicity/blindness in cats (rare/unproven, but reported)
- Gastrointestinal signs (nausea, vomiting)
- Potential CNS toxicity (seizures)
- Cartilage abnormalities in growing animals
- Potential retinal toxicity/blindness in cats (at high doses)
藥物相互作用
- Antacids / Dairy Products · Cations (Mg++, Al+++, Ca++) may bind to marbofloxacin and prevent its absorption; separate doses by at least 2 hours
- Antibiotics (aminoglycosides, 3rd-gen cephalosporins, extended-spectrum penicillins) · Unpredictable synergism may occur against some bacteria, particularly Pseudomonas aeruginosa
- Cyclosporine · May exacerbate nephrotoxicity and reduce the metabolism of systemically used cyclosporine
- Flunixin · May increase AUC and elimination half-life of the fluoroquinolone, and vice versa (extrapolated from enrofloxacin)
- Glyburide · Severe hypoglycemia possible
- Iron, Zinc (oral) · Decreased marbofloxacin 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 · Marbofloxacin may alter phenytoin levels
- Probenecid · Blocks tubular secretion and may increase blood level and half-life of marbofloxacin
- Quinidine · Increased risk for cardiotoxicity
- Sucralfate · May inhibit absorption of marbofloxacin; separate doses by at least 2 hours · major
監測
- Clinical efficacy (resolution of infection)
- Adverse effects (GI distress, CNS signs)
- Joint health/lameness in younger animals (if inadvertently used)
- Clinical efficacy and resolution of infection
- Culture and susceptibility results
- Signs of gastrointestinal upset
- Neurological signs (especially in patients with a history of seizures)
- Vision changes or mydriasis in cats
過量
Acute overdoses of marbofloxacin are unlikely to result in signs more serious than **anorexia or vomiting**, though other adverse effects (like CNS stimulation) could theoretically occur. * **Chronic Toxicity**: In safety studies, dogs receiving massive overdoses (55 mg/kg per day for 12 days) developed anorexia, vomiting, dehydration, tremors, red skin, facial swelling, lethargy, and weight loss. * **Treatment**: Management of overdose consists of drug withdrawal and symptomatic/supportive care. If ingestion was recent, gastrointestinal decontamination (emesis or activated charcoal) may be considered.
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。