磺胺氯噠嗪鈉
磺胺氯噠嗪鈉（Sulfachlorpyridazine sodium）是一種短至中效、低脂溶性的磺胺類抗菌藥物。在獸醫學中，主要用於治療腸道感染，特別是小於一個月大的小牛和豬的**大腸桿菌**（E. coli）感染。它也可作為一般用途的磺胺類藥物，以注射方式用於成年牛隻和其他物種。 **臨床要點：** * 作為一種**時間依賴性、抑菌性**抗生素，維持穩定的給藥間隔對於療效至關重要。 * 儘管細菌對磺胺類藥物的抗藥性日益普遍，但它在特定的群體健康管理中仍具有重要價值。 * 它在一般生理pH值的尿液中溶解度很高，但在脫水或尿液高度濃縮、偏酸性的病患中，仍有產生結晶尿的風險。
作用機制: Sulfonamides are generally bacteriostatic agents. They act as structural analogues of para-aminobenzoic acid (PABA). * They competitively inhibit the bacterial enzyme **dihydropteroate synthase**. * This blocks the incorporation of PABA into **dihydropteroic acid** → preventing the biosynthesis of **tetrahydrofolic acid** (the active form of folic acid). * Because mammalian cells utilize preformed dietary folic acid and do not synthesize their own, they are generally unaffected by this mechanism. * Efficacy is significantly reduced in the presence of pus, necrotic tissue, or extensive cellular debris, as these environments are rich in PABA which outcompetes the drug.
各物種劑量
- Diarrhea caused or complicated by E. coli in calves less than one month of age · 33-49.5 mg/kg PO, or IV twice daily · PO/IV · q12h · 1-5 days · Suggest initiating therapy with intravenous preparation and then changing to oral if possible
- Enteric bacterial infections (E. coli) · Mix 1/4 teaspoonful per liter of water and use as only supply of drinking water · PO · continuous · 5-10 days · Using the oral powder. May be effective for many E. coli enteric infections.
- Enteric bacterial infections (E. coli) · Mix 3/4 teaspoonsful per 2 quarts of water · PO · continuous · Using the oral powder. Fairly effective for enteric infections, particularly E. coli. Reserved for clients who are unable to give other medications by mouth or parenterally.
- E. coli and coccidiosis in pigeons · 1200 mg per gallon of drinking water · PO · continuous · Very effective for E. coli and it is a good coccidiostat.
- Colibacillosis · 44-77 mg/kg PO per day (divide dose and give twice daily if treating individual animals) · PO · q12h or q24h · 1-5 days
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
- Hypersensitivity to sulfonamides, thiazides, or sulfonylurea agents
- Severe renal impairment
- Severe hepatic impairment
不良反應
- Crystalluria
- Hematuria
- Renal tubule obstruction
- Keratoconjunctivitis sicca (KCS) in dogs
- Bone marrow depression
- Hypersensitivity reactions (rashes, dermatitis)
- Focal retinitis
- Fever
- Vomiting
- Nonseptic polyarthritis
- Muscle weakness, blindness, ataxia, and collapse (with rapid IV injection)
- Tissue irritation and necrosis (with IM or SC injection)
- Temporary depression of normal cellulytic function in the ruminoreticulum
藥物相互作用
- Antacids · May decrease the oral bioavailability of sulfonamides if administered concurrently
監測
- Clinical efficacy (resolution of diarrhea/infection)
- Adverse effects
- Hydration status and urine output
過量
Acute toxicity secondary to overdoses apparently occurs only rarely in veterinary species. * **Signs of Toxicity:** In addition to standard adverse effects, **CNS stimulation** and **myelin degeneration** have been noted after very high dosages. * **Treatment:** Treatment is largely supportive and symptomatic. Ensure aggressive fluid therapy to maintain urine output and prevent crystalluria.
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。