バンコマイシン

グリコペプチド系抗生物質

**バンコマイシン**は、強力な殺菌作用を持つグリコペプチド系抗生物質であり、人医療および獣医療において伝統的に「最後の切り札」と見なされています。 * **臨床的役割：** **メチシリン耐性黄色ブドウ球菌（MRSA）**、**メチシリン耐性偽中間期ブドウ球菌（MRSP）**、多剤耐性腸球菌など、多剤耐性グラム陽性菌による重篤で生命を脅かす感染症に厳格に限定して使用されます。 * **投与方法：** 全身性感染症の場合、**必ず**ゆっくりとした静脈内（IV）点滴として投与する必要があります。重度の組織壊死や疼痛を引き起こすため、皮下（SC）または筋肉内（IM）注射は絶対禁忌です。 * **経口投与：** バンコマイシンは消化管から吸収されないため、経口投与は**クロストリジウム・ディフィシル（*C. difficile*）による偽膜性腸炎**など、重篤な局所性腸管感染症の治療にのみ使用されます。 > **臨床のポイント：** 人間の生命を脅かす感染症治療におけるバンコマイシンの重要性を考慮すると、獣医療での使用には大きな議論があり、培養および感受性試験で他の抗生物質の選択肢がないことが確認された場合にのみ検討されるべきです。

作用機序: Vancomycin exerts its bactericidal effect primarily by inhibiting bacterial cell wall synthesis. * **Target Binding:** It binds tightly and non-covalently to the **D-alanyl-D-alanine** terminus of cell wall precursor units. * **Inhibition:** This massive steric hindrance prevents the enzymes (transglycosylases and transpeptidases) from incorporating the precursors into the growing peptidoglycan matrix → **inhibition of cell wall cross-linking**. * **Secondary Mechanisms:** It also alters bacterial cell-membrane permeability and interferes with RNA synthesis, making resistance more difficult to develop. * **Spectrum:** Activity is strictly limited to **gram-positive** organisms (staphylococci, streptococci, enterococci, *Clostridium*, *Listeria*). It is bactericidal against most susceptible bacteria but generally bacteriostatic against enterococci.

動物種別の用量

Cats

Confirmed bacteremia/septicemia for enterococci or staphylococci resistant to other commonly used antibiotics · 15 mg/kg IV over 30-60 minutes · IV · q6-8h
Serious infections · 15 mg/kg IV over 30-60 minutes · IV · q6h · For successful therapy, an aminoglycoside such as gentamicin or amikacin should also be administered.

Dogs

Confirmed bacteremia/septicemia for enterococci or staphylococci resistant to other commonly used antibiotics · 15 mg/kg IV over 30-60 minutes · IV · q6-8h
Serious infections · 15 mg/kg IV over 30-60 minutes · IV · q6h · For successful therapy, an aminoglycoside such as gentamicin or amikacin should also be administered.
C. difficile enterocolitis · 10-20 mg/kg PO · PO · q6h · 5-7 days · Oral vancomycin is not appreciably absorbed and is only effective for susceptible enteric infections.
Skin, urinary, soft tissue infections · 10-20 mg/kg IV · IV · q12h · 7-10 days
Systemic infections, bacteremia · 15 mg/kg IV · IV · q6h · 10 days

用量は獣医療従事者向けの臨床リファレンスです。必ず最新の添付文書と個々の患者で確認してください。

投与経路

IVPO

禁忌

Infections susceptible to other, lower-tier antibiotics
Intramuscular (IM), Subcutaneous (SC), or Intraperitoneal (IP) administration
Rapid IV bolus administration

有害事象

Nephrotoxicity (especially with concurrent nephrotoxic drugs)
Ototoxicity (hearing loss/vestibular signs)
Thrombophlebitis (if given IV too rapidly)
Severe hypotension or cardiac arrest (rare, associated with rapid IV bolus)
Severe tissue damage and pain (if given IM, SC, or IP)
Nausea and inappetence (with oral administration)
Reversible neutropenia (with high/prolonged dosing)
Hypersensitivity/dermatologic reactions (known in humans as 'Red Man Syndrome' due to histamine release)

薬物相互作用

Aminoglycosides (e.g., gentamicin, amikacin) · Synergistic antibacterial effect, but significantly increases the risk of ototoxicity and nephrotoxicity. Enhanced monitoring is required.
Anesthetic agents · May cause erythema and histamine-like flushing (reported in human pediatric patients).
Nephrotoxic drugs (e.g., amphotericin B, cisplatin) · Increased risk of severe nephrotoxicity; use together with extreme caution.

モニタリング

Renal function (BUN, Creatinine, Urinalysis) at baseline and periodically during treatment
Vancomycin serum trough levels (maintain above 5 mcg/mL; some specialists recommend 10-15 mcg/mL)
Periodic Complete Blood Count (CBC) if therapy is prolonged (to monitor for neutropenia)
Hearing and vestibular function (clinical observation)

過量投与

Patients with severe colitis taking an oral overdose could potentially absorb enough drug to cause systemic adverse effects. Intravenous overdoses significantly increase the risk of **ototoxicity** (hearing/balance damage) and **nephrotoxicity** (kidney damage). * **Toxicity Data:** The IV LD50 in mice is 400 mg/kg and in rats is 319 mg/kg. * **Treatment:** Treatment is primarily supportive care. Hemodialysis does not appear to remove the drug in significant amounts.

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。