替卡西林 / 克拉維酸
替卡西林/克拉維酸 (Timentin®) 是一種強效的注射用**廣效青黴素**（抗綠膿桿菌青黴素），並結合了**β-內醯胺酶抑制劑**。 * **擴展抗菌譜：** 添加克拉維酸可保護替卡西林免受酵素降解，將其療效擴展至產生β-內醯胺酶的*大腸桿菌*、*巴斯德桿菌*、*葡萄球菌*、*克雷伯氏菌*和*變形桿菌*。 * **臨床要點：** 在獸醫學中，它對*綠膿桿菌*的療效特別受到重視，通常保留用於嚴重的院內感染、敗血症或菌血症。 * **替代用途：** 雖然主要作為全身性醫院用藥，但常被調配成耳藥，用於輔助治療犬隻頑固的*綠膿桿菌*耳炎。
作用機制: **Ticarcillin** is a bactericidal beta-lactam antibiotic: * Binds to specific **Penicillin-Binding Proteins (PBPs)** (such as transpeptidases and carboxypeptidases) located inside the bacterial cytoplasmic membrane. * Inhibits bacterial cell wall mucopeptide synthesis → creates an osmotically unstable spheroplast → leads to cell lysis and death. **Clavulanate Potassium** is a "suicide inhibitor": * Competitively and irreversibly binds to **beta-lactamase enzymes** (including types II, III, IV, V, and staphylococcal penicillinases). * Prevents these enzymes from hydrolyzing the beta-lactam ring of ticarcillin, thereby restoring and expanding its antimicrobial spectrum. * *Note:* Type I beta-lactamases (often associated with *E. coli*, *Enterobacter*, and *Pseudomonas*) are generally not inhibited by clavulanic acid.
各物種劑量
- Sepsis · 40-50 mg/kg · IV · q6-8h · Dosed on the basis of ticarcillin content
- Pseudomonas sepsis/bacteremia · 40 mg/kg · IV · q6h · Dosed on the basis of ticarcillin content
- Resistant Pseudomonas infections · 50 mg/kg · IV or IM · 4 times daily · May need more frequent dosing or constant rate infusion for resistant infections
- Susceptible infections · 15-50 mg/kg · IV, IM or SC · q6-8h · Dosed on the basis of ticarcillin content
- Serious systemic infections · 15-25 mg/kg followed by CRI at 7.5-15 mg/kg/h · IV · CRI · As directed · Initial bolus followed by continuous rate infusion
- Pseudomonas otitis (adjunct) · 0.25-0.5 ml of a 100 mg/ml injectable ticarcillin solution · topical · q8h · As directed · Instil into the affected ear
- Susceptible infections · 50 mg/kg · IV · q6h · Dosed on the basis of ticarcillin content
- Neonatal septicemia (Foals) · 40-60 mg/kg · IV or IM · q8h · Dosed on the basis of ticarcillin content
- Susceptible infections (Foals) · 50 mg/kg · IV or IM · q6-8h · Dosed on the basis of ticarcillin content
- Intrauterine infusion · 3-6 grams with a minimum of 200 mL of saline · Intrauterine · every 4-6 h · Mares need to be treated frequently in order to maintain drug concentrations above MIC.
給藥途徑
禁忌症
- Documented hypersensitivity to penicillins or other beta-lactam antibiotics
- Known hypersensitivity to penicillins or other beta-lactam antibiotics
不良反應
- Hypersensitivity reactions (allergic reactions)
- Platelet dysfunction and bleeding (especially at high doses or with renal impairment)
- CNS effects including headache, giddiness, hallucinations, and seizures (at high doses)
- Pain at intramuscular (IM) injection sites
- Phlebitis or local vein irritation (IV administration)
- Antibiotic-associated diarrhea or colitis
- Nausea
- Diarrhoea
- Skin rashes
藥物相互作用
- Aminoglycosides (e.g., amikacin, gentamicin, tobramycin) · In vitro synergy against certain bacteria; however, penicillins can chemically inactivate aminoglycosides in vitro and in vivo (especially in renal failure or at massive doses). Do not mix in the same syringe or IV line.
- Probenecid · Reduces renal tubular secretion of ticarcillin, maintaining higher systemic levels for a longer duration (does not affect clavulanate elimination).
- Warfarin · Increased risk of bleeding due to potential ticarcillin-induced platelet dysfunction; use with caution.
- Heparin · Increased risk of bleeding due to potential ticarcillin-induced platelet dysfunction; use with caution.
- Aminoglycosides (e.g., gentamicin) · Mutual inactivation if mixed in the same syringe. However, there is significant synergism in vivo against Pseudomonas when administered separately. · major
監測
- Clinical efficacy (resolution of clinical signs, WBC count, fever)
- Renal function (in patients with pre-existing impairment)
- Signs of bleeding or CNS abnormalities (if on high doses)
- Clinical signs of infection resolution
- Renal function (in prolonged use)
- Signs of hypersensitivity or adverse gastrointestinal effects
過量
A single inadvertent overdose is unlikely to cause significant morbidity. However, very high dosages of parenteral penicillins (especially in patients with underlying renal disease) have induced **CNS effects** (hallucinations, headaches, seizures) and alterations in **platelet function** leading to bleeding.
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。