托芬那酸
Tolfenamic Acid
N-(2-methyl-3-chlorophenyl)anthranilic acid
別名: Tolfedine · Tolfejec · acidum tolfenamicum · Bifenac · Clotam · Clotan · Flocur · Gantil · Migea · Polmonin · Purfalox · Rociclyn · Tolfamic · Turbaund
由 VetSheet 獸醫團隊審訂更新於 2026年4月5日本內容以實證獸醫文獻為本
經審核的 v13 劑量證據
結構化劑量計算證據NSAID (extra-label) — Acute pain
須由已驗證獸醫確認
- q24h
NA
必須同時考慮的臨床上下文 (3)
- NSAID (extra-label):
- Unless otherwise labeled, store tolfenamic acid products at room temperature. Protect from light. Refer to the injectable product label for discard dating following the first vial puncture.
- ■ Should give oral medicine with food.
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。
概覽
托芬那酸 (Tolfenamic acid) 是一種屬於滅酸類 (fenamate) 的非類固醇消炎止痛藥 (NSAID)，化學結構上與甲氯芬那酸 (meclofenamic acid) 相關。主要用於鎮痛、抗發炎和解熱。
主要臨床特徵：
- 雙重作用： 與許多傳統 NSAID 不同，滅酸類藥物不僅能抑制前列腺素的合成，還能直接阻斷前列腺素受體，從而提供更佳的鎮痛效果。
- 脈衝式給藥： 對於犬隻的慢性疾病，通常採用獨特的「脈衝式」給藥計畫（例如每週連續給藥 3-5 天），以在維持療效的同時，將胃腸道和腎臟毒性降至最低。
- 血小板影響： 具有顯著的抗血栓素活性，會損害血小板凝集功能。因此，不建議在手術前使用。
- 藥物取得： 雖然在加拿大、歐洲和澳洲廣泛核准用於小動物和大型動物，但目前在美國並未上市。
臨床要點： 與食物一起服用會增加腸肝循環，進而提高其生物利用度，但與空腹狀態相比，也可能造成吸收上的變異性增加。
作用機制
Tolfenamic acid exerts its effects through multiple pathways in the inflammatory cascade:
- Cyclooxygenase (COX) Inhibition: It is a potent inhibitor of the COX enzyme, which prevents the conversion of arachidonic acid → prostaglandins (PGs) and thromboxanes (TXA2). This reduces inflammation, pain, and fever.
- Direct Receptor Antagonism: Uniquely among NSAID classes, fenamates directly block the binding of synthesized prostaglandins to their respective tissue receptors (e.g., EP receptors), providing a secondary mechanism of action against pain and inflammation.
- Anti-thromboxane Activity: By inhibiting TXA2 synthesis, it significantly impairs platelet aggregation and normal clotting function.
安全性與警告
禁忌症
- Hypersensitivity to tolfenamic acid or other fenamates (e.g., meclofenamic acid)
- Active gastrointestinal bleeding or ulceration
- Pre-surgical administration (due to anti-thromboxane/platelet effects)
- Dehydrated, hypovolemic, or hypotensive patients
- Patients with gastrointestinal disease
- Patients with blood clotting problems
- Pregnant animals
- Animals under 6 weeks of age
- Intramuscular (IM) administration in cats
不良反應
- Gastrointestinal ulceration (at high doses)
- Platelet dysfunction/prolonged bleeding time
- Potential nephrotoxicity (especially in dehydrated patients)
- Gastrointestinal signs (vomiting, diarrhea, anorexia)
- Gastrointestinal ulceration and bleeding
- Renal toxicity (especially during hypotension)
- Potential precipitation of cardiac failure (rare/unknown risk in animals)
注意事項
Use with extreme caution in patients with decreased renal or hepatic function. Ensure patients are well-hydrated to mitigate nephrotoxic risks. Like other NSAIDs, tolfenamic acid should be used with caution during pregnancy. Do not use pre-surgically due to its effects on platelet function.
藥物相互作用
May increase the risk of gastrointestinal toxicity (e.g., ulceration, bleeding, vomiting, diarrhea).
Concomitant therapy may increase the occurrence of gastric ulceration; avoid concurrent use.
NSAIDs may increase serum levels of digoxin.
May increase plasma levels of NSAIDs; potentially affects tolfenamic acid levels in dogs.
NSAIDs may reduce the saluretic and diuretic effects of furosemide.
Serious toxicity has occurred with concomitant NSAID use; use together with extreme caution.
May enhance the risk of nephrotoxicity.
May increase the risk of gastrointestinal toxicity (e.g., ulceration, bleeding, vomiting, diarrhea).
Tolfenamic acid is 98-99% protein-bound; may displace highly protein-bound drugs like warfarin, increasing bleeding risk. Monitor closely.
Increased risk of gastrointestinal ulceration and bleeding. Do not administer concurrently or within 24 hours.
Increased risk of nephrotoxicity.
監測
- Clinical efficacy (pain scores, resolution of inflammation)
- Adverse effects (vomiting, diarrhea, anorexia)
- Renal function (BUN, Creatinine, SDMA, USG) with prolonged use
- Signs of GI bleeding (melena, pale mucous membranes)
- Clinical signs of gastrointestinal toxicity (vomiting, diarrhea, melena, anorexia)
- Renal parameters (BUN, creatinine, USG), especially in perioperative or hypotensive patients
- Liver enzymes in patients receiving prolonged therapy
藥物動力學
半衰期
吸收
Absorbed after oral administration. Peak levels in dogs occur 2-4 hours post-dosing. Enterohepatic recirculation is increased with food, which increases bioavailability but also creates more variability compared to fasted dogs.
分佈
Volume of distribution in dogs is approximately 1.2 L/kg. Highly protein bound (98-99%).
代謝
Undergoes hepatic metabolism and enterohepatic recycling.
排除
Clearance is significantly increased in dogs with experimentally induced renal failure, presumably via increased hepatic metabolism or enterohepatic recycling. Duration of anti-inflammatory effect is 24-36 hours.
過量
Acute toxicity data is limited. Experimental studies in dogs and cats did not demonstrate significant renal or GI toxicity until doses exceeded 10 times the labeled dose.
Treatment Protocol:
- Decontamination: Empty the gut following recent oral ingestion (emesis induction, activated charcoal).
- Supportive Care: Institute IV fluid therapy to maintain hydration and support renal perfusion.
- Seizure Control: Use IV diazepam if seizures occur.
- Monitoring: Closely monitor for signs of gastrointestinal bleeding (melena, hematemesis). Monitor electrolyte and fluid balance carefully, and manage any acute renal failure using established veterinary guidelines.
可用產品
劑型
- Tablets
- Injection (Solution)
- 40 mg/ml injectable solution
- 6 mg oral tablet
- 20 mg oral tablet
- 60 mg oral tablet
獸醫用
- Tolfenamic Acid Tablets: 6 mg, 30 mg, 60 mg
- Tolfenamic Acid Injection: 40 mg/mL
- Tolfedine 40 mg/ml solution for injection
- Tolfedine 6 mg tablets
- Tolfedine 20 mg tablets
- Tolfedine 60 mg tablets
人用標示
- None in the USA
各地核准狀態
Authorized for preoperative administration to cats and dogs.
POM-V classification.
暫無法規資料: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
儲存與穩定性
Unless otherwise labeled, store tolfenamic acid tablets and solution at room temperature.
飼主須知
托芬那酸是一種用於緩解寵物疼痛和發炎的藥物。
重要給藥指引：
- 遵守給藥時間表： 如果您的獸醫師開立了每週的給藥計畫（例如，連續給藥 3 到 5 天，然後在一週的剩餘時間停藥），務必嚴格遵守。這種「脈衝式」給藥計畫有助於預防嚴重的副作用。
- 與食物一起餵食： 將此藥物與食物一起餵食可以幫助您的寵物更好地吸收，並可能減少腸胃不適。
- 注意事項： 如果您的寵物出現嘔吐、腹瀉、食慾不振、飲水量或排尿量增加，或者您發現深色柏油狀糞便（這可能是胃出血的跡象），請立即停藥並聯絡您的獸醫師。
- 請勿混合用藥： 在寵物服用托芬那酸期間，絕對不要給予人類的止痛藥（如阿斯匹靈或布洛芬）或其他獸醫用 NSAID，因為這可能會導致致命的胃潰瘍或腎衰竭。
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