酮咯酸
**酮咯酸 (Ketorolac)** 是一種強效的非類固醇消炎止痛藥 (NSAID)，在獸醫學中主要用於短期的鎮痛治療。 - **臨床要點**：雖然酮咯酸能提供極佳的止痛效果（在人類醫學中常與鴉片類藥物相提並論），但由於目前已有更安全的獸醫專用 NSAID，且其在犬貓身上引發**胃腸道毒性**（潰瘍與穿孔）及**腎臟毒性**的風險極高，因此其使用備受爭議且通常不建議。 - 若必須用於犬隻，多數臨床獸醫師會嚴格限制療程在**3天以內**，並強烈建議同時給予胃腸保護劑如**米索前列醇 (misoprostol)**（可合併或不合併使用硫糖鋁）。
作用機制: Ketorolac exerts its analgesic, anti-inflammatory, and antipyretic effects by non-selectively inhibiting **cyclooxygenase (COX-1 and COX-2)** enzymes. **Arachidonic Acid** → **COX-1/COX-2 Inhibition** → Decreased synthesis of **prostaglandins** and **thromboxanes**. By blocking prostaglandin production, it reduces inflammation and pain signaling. However, the profound inhibition of constitutive COX-1 also depletes protective prostaglandins in the gastric mucosa and kidneys, leading to its severe ulcerogenic and nephrotoxic side effect profile in small animals.
各物種劑量
- As an analgesic · 0.25 mg/kg IM q8-12h for one or two doses · IM · q8-12h · 1-2 doses
- Anterior uveitis and ulcerative keratitis · 1 drop per eye · topical · q6-24h · Frequency depends on the severity of inflammation.
- As an analgesic (Mice) · 0.7-10 mg/kg PO once daily · PO · once daily
- As an analgesic (Rats) · 3-5 mg/kg PO once to twice a day; 1 mg/kg IM once to twice a day · PO, IM · once to twice a day
- As an analgesic · 0.3-0.7 mg/kg IV , IM, SC, PO three times daily · IV, IM, SC, PO · three times daily
- As an analgesic · 0.5 mg/kg IV three times daily or 0.3 mg/kg PO twice daily · IV, PO · TID (IV) or BID (PO) · < 3 days · Repeated doses have considerable potential for causing GI or renal toxicity. Treated dogs should receive misoprostol.
- As an analgesic · 0.3-0.5 mg/kg IV , IM q8-12h for one or two doses · IV, IM · q8-12h · 1-2 doses
- Anterior uveitis and ulcerative keratitis · 1 drop per eye · topical · q6-24h · Frequency depends on the severity of inflammation.
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
- Active GI ulcers
- History of hypersensitivity to ketorolac
- Pre-existing hematologic, renal, or hepatic disease (relative contraindication)
- Known hypersensitivity to NSAIDs
- Use with extreme caution in patients with deep or progressive corneal ulcers
不良反應
- Gastrointestinal ulceration and erosion
- Gastrointestinal perforation
- Renal toxicity
- Hepatic toxicity
- Platelet inhibition (increased bleeding risk)
- Local ocular irritation
- Delayed corneal epithelial healing
- Increased intraocular pressure (IOP)
- Corneal 'melting' (keratomalacia) - reported in humans, theoretical risk in animals
藥物相互作用
- ACE INHIBITORS · Increased risk for nephrotoxicity
- ALPRAZOLAM · Hallucinations reported in some human patients taking with ketorolac
- AMINOGLYCOSIDES (gentamicin, amikacin, etc.) · Increased risk for nephrotoxicity
- ANTICOAGULANTS (heparin, LMWH, warfarin) · Increased risk for bleeding possible
- ASPIRIN · Increased likelihood of GI adverse effects (blood loss)
- BISPHOSPHONATES (alendronate, etc.) · May increase risk for GI ulceration
- CORTICOSTEROIDS · Concomitant administration with NSAIDs may significantly increase the risks for GI adverse effects
- CYCLOSPORINE · May increase risk for nephrotoxicity
- FLUCONAZOLE · May increase NSAID levels
- FLUOXETINE · Hallucinations reported in some human patients taking with ketorolac
- FUROSEMIDE · Ketorolac may reduce the saluretic and diuretic effects of furosemide
- METHOTREXATE · Serious toxicity has occurred when NSAIDs have been used concomitantly; use together with extreme caution
- MUSCLE RELAXANTS, NONDEPOLARIZING · Ketorolac may potentiate effects
監測
- Analgesic and anti-inflammatory efficacy
- Gastrointestinal signs (appetite, vomiting, diarrhea, occult blood in feces)
- Renal function parameters (BUN, creatinine, urinalysis) with repeated use
- Intraocular pressure (IOP), especially in predisposed breeds
- Corneal healing via fluorescein staining
- Signs of corneal melting or worsening ulceration
過量
Ketorolac has a narrow margin of safety in small animals. - **Cats**: Have developed renal toxicity at doses as low as 0.7 mg/kg. - **Mice**: The oral LD50 is 200 mg/kg. - **Clinical Signs**: GI effects, including severe GI ulceration and bleeding, are highly likely in overdoses in small animals. Metabolic acidosis has been reported in humans. - **Treatment**: Consider GI emptying for large, recent overdoses. Patients must be closely monitored for GI bleeding and renal impairment. Treat aggressively with GI protectants (sucralfate) and consider giving misoprostol early.
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。