乙醯氧肟酸
**乙醯氧肟酸 (AHA)** 是一種特殊藥物，主要用於犬隻作為**頑固性磷酸銨鎂結石**（膀胱結石）及由**產尿素酶細菌**引起的慢性泌尿道感染的輔助治療。 * **臨床要點**：由於副作用較大，通常僅在標準抗生素和處方飲食無效的難治性病例中使用。 * **警告**：貓咪絕對禁用，具有嚴重毒性。
作用機制: AHA acts as a potent, reversible inhibitor of the bacterial enzyme **urease**. * **Urease** normally hydrolyzes urea → ammonia + carbon dioxide. * By inhibiting **urease**, AHA → decreases urinary ammonia, bicarbonate, and carbonate concentrations → prevents the alkalinization of urine (keeps pH lower). * This acidic environment increases the solubility of struvite (magnesium ammonium phosphate) and carbonate-apatite crystals, and enhances the efficacy of concurrent antimicrobial therapy (e.g., carbenicillin, gentamicin, clindamycin, trimethoprim-sulfa, or chloramphenicol).
各物種劑量
- Adjunctive therapy of persistent struvite uroliths and persistent urease-producing bacteria after treating with antibiotics and calculolytic diets · 12.5 mg/kg twice daily PO · PO · twice daily
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
- Cats (highly toxic)
- Patients with poor renal function (e.g., serum creatinine >2.5 mg/dL)
- Pregnancy (FDA Category X - severe teratogenic effects)
不良反應
- Anorexia
- Vomiting
- Mouth and esophageal ulcers
- Hemolytic anemia
- Hyperbilirubinemia
- Bilirubinuria
- CNS disturbances (anxiety, depression, tremulousness)
- Reticulocytosis
- Bone marrow depression
- Phlebitis
- Skin rashes and alopecia
藥物相互作用
- Iron salts · AHA may chelate iron salts in the gut if given concomitantly, reducing absorption.
- Methenamine · AHA may have a synergistic effect with methenamine in inhibiting urine pH increases caused by urease-producing Proteus spp., and may potentiate antibacterial effects.
- Alcohol · In humans, concurrent use of AHA with alcohol has resulted in skin rashes.
監測
- CBC (Complete Blood Count)
- Renal function (including urinalysis)
- Hepatic function (specifically bilirubin levels)
過量
Acute overdoses can lead to severe hematologic and neurologic signs. * **Clinical Signs**: Anorexia, tremors, lethargy, vomiting, and anxiety. * **Hematologic Effects**: Increased reticulocyte counts and severe **hemolytic reactions**. Mild overdoses over several weeks can also result in hemolysis, particularly in patients with reduced renal function. * **Treatment**: Intensive hematologic monitoring with adjunctive supportive therapy, including possible blood transfusions.
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。