テポキサリン
テポキサリンは、シクロオキシゲナーゼ（COX）およびリポキシゲナーゼ（LOX）経路の両方を阻害するユニークな**二重阻害薬**です。主に**犬の変形性関節症**に伴う疼痛および炎症の管理に適応されます。 * 口腔内崩壊錠（口の中で溶ける錠剤）として提供されており、投薬が困難な犬に非常に有用です。 * ロイコトリエンに対する阻害作用があるため、犬のアレルギー疾患の補助治療としての可能性にも関心が寄せられています。 * **臨床のポイント**: LOX阻害による理論的な消化管保護作用にもかかわらず、臨床データでは他の最新のFDA承認COX-2選択的NSAIDと比較して嘔吐や下痢を引き起こす可能性が高いことが示唆されています。
作用機序: 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.
動物種別の用量
- 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.
用量は獣医療従事者向けの臨床リファレンスです。必ず最新の添付文書と個々の患者で確認してください。
投与経路
禁忌
- 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)
有害事象
- Diarrhea
- Vomiting
- Anorexia/inappetence
- Enteritis
- Lethargy
- Incoordination (<1%)
- Incontinence (<1%)
- Increased appetite (<1%)
- Eating grass (<1%)
- Flatulence (<1%)
- Hair loss (<1%)
- Trembling (<1%)
薬物相互作用
- 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.
モニタリング
- 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.)
過量投与
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 の薬剤リファレンスは、獣医療従事者向けの臨床意思決定支援を目的としており、専門的判断やメーカーの最新添付文書に代わるものではありません。