丹諾沙星
丹諾沙星是一種獸醫專用的注射型**氟喹諾酮類抗生素**，主要用於治療肉牛的牛呼吸道疾病 (BRD)。它對 *Mannheimia haemolytica* 和 *Pasteurella multocida* 等主要呼吸道病原體具有濃度依賴性的殺菌活性。 **臨床要點：** * 與其他氟喹諾酮類藥物一樣，它具有極佳的組織穿透力，特別是肺部組織，使其對呼吸道感染非常有效。 * 具有高分佈體積，並能良好地濃縮於滲出液和漏出液中。 * **法規警告：** 美國 FDA 嚴格禁止在經濟動物（食用動物）中對氟喹諾酮類藥物進行標示外使用 (extra-label use)。
作用機制: Fluoroquinolones are bactericidal antibiotics that act by inhibiting bacterial DNA replication and transcription. * They enter the bacterium and inhibit **DNA gyrase** (topoisomerase II) and **topoisomerase IV**. * Inhibition of **DNA gyrase** → prevents DNA supercoiling → halts DNA replication. * Inhibition of **topoisomerase IV** → interferes with the separation of interlinked replicated DNA molecules. * This dual action leads to rapid bacterial cell death. The bactericidal activity is **concentration-dependent** rather than time-dependent.
各物種劑量
- Ophthalmic infections · 1 drop to affected eye · topical · q6h · As directed by veterinarian · Intensive therapy: q30-120min for short-term use (1-2 days).
- Bovine Respiratory Disease (BRD) · 6 mg/kg (1.5 mL per 100 lb body weight) SC · SC · Repeat once in approximately 48 hours · 2 doses total · Administered dosage volume should not exceed 15 mL per injection site.
- Ophthalmic infections · 1 drop to affected eye · topical · q6h · As directed by veterinarian · Intensive therapy: q30-120min for short-term use (1-2 days).
劑量為合格獸醫專業人員的臨床參考。請務必對照最新藥品仿單及個別病患確認。
給藥途徑
禁忌症
- Extra-label use in food-producing animals (FDA prohibited)
- Lactating dairy cattle (where milk is for human consumption)
- Veal calves
- Animals with known or suspected CNS disorders (relative contraindication)
- Known hypersensitivity to ofloxacin or other fluoroquinolones
不良反應
- Hypersensitivity reactions (uncommon)
- Lameness or arthropathies (especially in young animals/calves)
- Local tissue reaction at the subcutaneous injection site (may result in trim loss)
- Mild, transient ocular irritation or stinging upon application (general class effect)
- Conjunctival hyperemia (rare)
藥物相互作用
- Theophylline (aminophylline) · Potential increase in serum concentrations of theophylline; increased monitoring of theophylline concentrations is recommended
監測
- Clinical efficacy
- Injection site reactions
- Signs of lameness or CNS stimulation
- Clinical response to therapy (resolution of ocular discharge, inflammation, or ulceration)
- Culture and sensitivity testing prior to and during prolonged treatment if no improvement
過量
Limited information is available for cattle. High dosages (18-60 mg/kg for 3-6 days) in feeder calves can cause **arthropathies/lameness** (consistent with other fluoroquinolones), **CNS stimulation** (ataxia, nystagmus, tremors), inappetence, recumbency, depression, and exophthalmos. Some calves receiving 18 mg/kg twice 48 hours apart developed nasal pad erythema. In adult dogs, 2.4 mg/kg/day PO for 90 days resulted in no observable adverse effects.
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。