乙醯胺酚 / 撲熱息痛
乙醯胺酚（撲熱息痛）是一種合成的非鴉片類鎮痛解熱劑。 **臨床要點與獸醫背景：** * 由於缺乏葡萄糖醛酸轉移酶，導致有毒代謝物NAPQI積聚，**對貓和雪貂具有極高毒性**（任何劑量皆然）。 * 偶爾用於狗和小型哺乳動物以緩解輕至中度疼痛，特別是在禁用非類固醇消炎藥（NSAIDs）的情況下（例如腎功能不全）。 * 在臨床劑量下缺乏顯著的周邊抗發炎活性，且不抑制血小板功能。 * 常與鴉片類藥物（如可待因、氫可酮）製成複方以產生協同鎮痛效果。
作用機制: Produces analgesia and antipyresis via weak, reversible, isoform-nonspecific inhibition of **cyclooxygenase (COX-3 / COX-1-v1)** in the central nervous system. **Mechanism Pathway:** Inhibition of central **COX** enzymes → decreased **prostaglandin** synthesis in the CNS → elevation of the pain threshold and alteration of the hypothalamic thermoregulatory center → analgesia and antipyresis. *Note: It lacks significant peripheral COX-1 or COX-2 inhibition, which explains its lack of anti-inflammatory and anti-platelet effects.*
各物種劑量
- Analgesic (Rabbits) · 1-2 mg/mL in drinking water · PO · Ad libitum · Using Children's Tylenol. Effective for controlling low-grade nociception.
- Analgesic (Mice, Rats, Gerbils, Hamsters, Guinea pigs, Chinchillas) · 1-2 mg/mL in drinking water · PO · Ad libitum
- Analgesic · 15 mg/kg PO q8h · PO · q8h
- Analgesic · 10 mg/kg PO q12h · PO · q12h
- Analgesic · 10-15 mg/kg PO q12h · PO · q12h · 5 days
- Treatment of degenerative myelopathy (in German Shepherds) · 5 mg/kg PO (not to exceed 20 mg/kg per day) · PO · 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
- Cats (at any dosage)
- Ferrets
- Sugar Gliders
- Hedgehogs
不良反應
- Methemoglobinemia (especially in cats and dogs at high doses)
- Hepatotoxicity (liver necrosis)
- Renal effects
- Gastrointestinal disturbances
- Facial and paw swelling (edema)
- Keratoconjunctivitis sicca (KCS)
- Cyanosis
- Hypothermia
藥物相互作用
- Other Analgesics · Chronic use with acetaminophen may lead to renal pathologies
- Barbiturates · Increased conversion of acetaminophen to hepatotoxic metabolites; potentially increased risk for hepatotoxicity
- Doxorubicin · May deplete hepatic glutathione, thereby leading to increased hepatic toxicity
- Halothane · Not recommended for postoperative analgesia in animals that received halothane anesthesia
- Isoniazid · Possible increased risk of hepatotoxicity
- Phenothiazines · Possible increased risk for hypothermia
- Propylene Glycol · May increase the severity of acetaminophen-induced methemoglobinemia or Heinz body formation
- Warfarin · Large doses may potentiate anticoagulant effects
監測
- Liver enzymes (ALT, AST, ALP)
- Renal function (BUN, Creatinine)
- Hematologic parameters (CBC for methemoglobinemia or Heinz bodies)
- Clinical signs of toxicity (edema, cyanosis, lethargy)
過量
**Acute Toxicity & Overdose:** * **Clinical Signs:** Methemoglobinemia (brown blood/mucous membranes), liver necrosis, renal effects, facial and paw swelling, keratoconjunctivitis sicca (KCS), vomiting, lethargy, cyanosis, hypothermia. * **Species Differences:** Liver effects are more common in dogs; facial/paw swelling and methemoglobinemia are more common in cats. * **Treatment:** Standard gut emptying techniques (emesis/lavage) and activated charcoal if recent. Administer **acetylcysteine (NAC)** as a glutathione precursor to bind toxic metabolites. Supportive care includes **s-adenosyl methionine (SAMe)**, oxygen therapy, IV fluids, and blood transfusions or methylene blue for severe methemoglobinemia.
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。