チカルシリン / クラブラン酸
チカルシリン/クラブラン酸（Timentin®）は、強力な注射用**広域ペニシリン**（抗緑膿菌ペニシリン）に**β-ラクタマーゼ阻害薬**を配合した薬剤です。 * **抗菌スペクトルの拡大：** クラブラン酸の添加によりチカルシリンが酵素による分解から保護され、β-ラクタマーゼを産生する*大腸菌*、*パスツレラ属*、*ブドウ球菌属*、*クレブシエラ*、*プロテウス*に対する有効性が拡大します。 * **臨床的ポイント：** 獣医学においては、*緑膿菌*に対する有効性が特に評価されており、重度の院内感染、敗血症、菌血症のためにしばしば温存されます。 * **代替用途：** 主に全身用の院内薬剤ですが、犬の難治性*緑膿菌*性外耳炎の補助治療として、点耳薬として調剤されることがよくあります。
作用機序: **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.
動物種別の用量
- 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.
投与経路
禁忌
- Documented hypersensitivity to penicillins or other beta-lactam antibiotics
- Known hypersensitivity to penicillins or other beta-lactam antibiotics
有害事象
- 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
薬物相互作用
- 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
モニタリング
- 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
過量投与
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 の薬剤リファレンスは、獣医療従事者向けの臨床意思決定支援を目的としており、専門的判断やメーカーの最新添付文書に代わるものではありません。