特波沙林
特波沙林 (Tepoxalin) 是一種獨特的**雙重抑制劑**，能同時抑制環氧合酶 (COX) 和脂氧合酶 (LOX) 途徑。主要用於治療**犬骨關節炎**相關的疼痛與發炎。 * 具有快速崩解錠劑型（口溶錠），非常適合難以餵藥的犬隻。 * 由於其對白三烯素的抑制作用，目前也有研究探討其作為犬過敏性疾病輔助治療的潛力。 * **臨床提示**：儘管抑制 LOX 理論上具有保護胃腸道的作用，但臨床數據顯示，與其他現代 FDA 核准的 COX-2 選擇性 NSAID 相比，它可能引起更多的嘔吐和腹瀉。
作用機制: Tepoxalin blocks the arachidonic acid cascade at two key points: * **Cyclooxygenase (COX-1 and COX-2)** → Decreases production of pro-inflammatory **prostaglandins** (mediators of pain, hyperpyrexia, and inflammation). * **5-Lipoxygenase (5-LOX)** → Decreases production of **leukotrienes** (e.g., LTB4). *Pharmacological Note*: LTB4 is a potent chemoattractant for neutrophils and contributes to GI mucosal damage by increasing cytokine production and release of proteinases. By inhibiting LOX, tepoxalin theoretically mitigates the GI ulcerogenic effects typically seen with COX-1 inhibition, though clinical GI side effects still occur. LOX inhibition in dogs persists for only about 6 hours after dosing.
各物種劑量
- Pain and inflammation associated with osteoarthritis · 20 mg/kg PO (or 10 mg/kg PO) on first day; subsequently give 10 mg/kg PO once daily · PO · q24h · Based on clinical response and patient tolerance · On first day of treatment give 20 mg/kg PO (or 10 mg/kg PO); subsequently give 10 mg/kg PO once daily.
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。
給藥途徑
禁忌症
- Prior hypersensitivity reactions to tepoxalin
- Active gastrointestinal ulcers
- Dogs weighing less than 3 kg (cannot be accurately dosed)
- Dogs less than 6 months old (safety not established)
不良反應
- Diarrhea
- Vomiting
- Anorexia/inappetence
- Enteritis
- Lethargy
- Incoordination (<1%)
- Incontinence (<1%)
- Increased appetite (<1%)
- Eating grass (<1%)
- Flatulence (<1%)
- Hair loss (<1%)
- Trembling (<1%)
藥物相互作用
- Aspirin · May increase the risk of gastrointestinal toxicity (e.g., ulceration, bleeding, vomiting, diarrhea)
- Corticosteroids · May increase the occurrence of gastric ulceration; avoid concomitant use
- Digoxin · NSAIDs may increase serum levels of digoxin
- Fluconazole · May increase plasma levels of tepoxalin (extrapolated from human celecoxib data)
- Furosemide · NSAIDs may reduce saluretic and diuretic effects
- Methotrexate · Serious toxicity has occurred with concomitant NSAID use; use with extreme caution
- Nephrotoxic Drugs (e.g., aminoglycosides, amphotericin B) · May enhance the risk of nephrotoxicity
- Other NSAIDs · May increase the risk of gastrointestinal toxicity (e.g., ulceration, bleeding, vomiting, diarrhea)
- Warfarin · Tepoxalin is highly protein bound (98-99%); may displace warfarin and increase bleeding risk. Monitor closely.
監測
- Clinical efficacy (improvement in mobility/pain)
- Baseline and periodic CBC
- Chemistry panel (including bilirubin and serum creatinine)
- Signs associated with adverse effects (GI effects, appetite, vomiting, diarrhea, etc.)
過量
Information on acute overdosage is limited. Chronic overdosage (300 mg/kg/day for 6 months) in dogs caused decreases in total protein, albumin, and calcium concentrations, with gastric lesions noted at necropsy. An acute overdose may cause significant GI distress, ulceration, and GI bleeding. * **Treatment**: Treat supportively. Monitor CBC, hydration status, renal function, and for evidence of GI bleeding. Contact an animal poison control center for further guidance.
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。