頭孢維星
Cefovecin
Cefovecin sodium
別名: Convenia · UK-287074-02 · cefovecina sodica · céfovécine sodique · natrii cefovecinum
由 VetSheet 獸醫團隊審訂更新於 2026年4月5日本內容以實證獸醫文獻為本
經審核的 v13 劑量證據
結構化劑量計算證據UTI and severe infections of the gingival and periodontal tissues (extra-label)
須由已驗證獸醫確認
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劑量為持牌獸醫專業人員的臨床參考。請務必對照最新藥品說明書及個別病患確認。
概覽
頭孢維星 (Cefovecin) 是一種專為犬貓設計的長效注射型第三代頭孢菌素類抗生素。
主要臨床特徵：
- 提高依從性： 其主要臨床優勢在於解決飼主難以按時餵藥的問題，或適用於對口服抗生素耐受性差、吸收不良的病患。
- 抗菌譜： 作為第三代頭孢菌素，具有廣效抗菌活性。對常見的皮膚病原體（如假中間葡萄球菌、犬鏈球菌G群及多殺性巴斯德桿菌）高度有效。
- 局限性： 對綠膿桿菌 (Pseudomonas spp.) 或腸球菌 無效。此外，由於其高蛋白結合率，在標準標籤劑量下，無法達到足夠的血清濃度來治療全身性（非泌尿道）的大腸桿菌感染。
- 藥代動力學特點： 其極長的半衰期歸因於對血漿蛋白的高親和力及緩慢的解離率，使得單次注射即可根據目標病原體的最低抑菌濃度 (MIC) 提供數天至數週的治療性抗菌濃度。
作用機制
Cefovecin is a time-dependent, bactericidal beta-lactam antibiotic.
- Mechanism: Like other cephalosporins, cefovecin mimics the D-alanyl-D-alanine terminal of the peptidoglycan chain. It binds to and irreversibly inhibits bacterial Penicillin-Binding Proteins (PBPs), specifically transpeptidases and carboxypeptidases.
- Pathway: Inhibition of PBPs → Prevents cross-linking of peptidoglycan chains → Weakens the bacterial cell wall → Osmotic instability → Bacterial cell lysis and death.
- Efficacy: Because it is a time-dependent antibiotic, maintaining free (unbound) drug concentrations above the Minimum Inhibitory Concentration (MIC) of the target pathogen for a significant portion of the dosing interval is critical for its bactericidal efficacy.
安全性與警告
禁忌症
- Known allergy or hypersensitivity to cefovecin, other cephalosporins, or penicillins (beta-lactams)
- Small herbivores (e.g., guinea pigs, rabbits) due to risk of fatal dysbiosis
- Dogs or cats less than 4 months of age (USA label) or less than 8 weeks of age (UK label)
不良反應
- Lethargy and depression
- Anorexia
- Vomiting
- Mild to moderate increases in liver enzymes (ALT, GGT)
- Increases in BUN and moderately elevated serum creatinine (observed in cats)
- Injection site irritation, vocalization, and transient edema
- Hypersensitivity reactions and anaphylaxis (rare but potentially fatal)
- Myelotoxicity creating toxic neutropenia (rare class effect)
- Anemia, thrombocytopenia, and prolonged coagulation times (rare class effect)
注意事項
Prolonged Duration Warning: Because cefovecin can persist in the body for up to 65 days, any adverse reactions (such as hypersensitivity or gastrointestinal upset) may require prolonged symptomatic and supportive treatment.
- Renal Impairment: Cefovecin is primarily eliminated via renal mechanisms. Use with caution in animals with severe renal dysfunction.
- Breeding/Lactation: Safe use in breeding or lactating animals has not been definitively established, though cephalosporins are generally considered safe. Weigh risks vs. benefits.
- Laboratory Interference: May cause false-positive urine glucose (copper reduction methods), falsely elevated creatinine (Jaffe reaction at high doses), falsely lowered albumin, and false-positive direct Coombs' tests.
藥物相互作用
May compete for plasma protein binding sites, potentially increasing the free (active) concentrations of either drug.
May compete for plasma protein binding sites.
May compete for plasma protein binding sites.
May compete for plasma protein binding sites.
Concurrent use of highly protein-bound drugs may compete with cefovecin binding and cause adverse reactions, though actual clinical significance is not fully established.
Competition for plasma protein binding, potentially altering free drug concentrations
監測
- Clinical efficacy (resolution of clinical signs of infection)
- Adverse effects (e.g., gastrointestinal upset, lethargy, injection site reactions)
- Renal and hepatic parameters in patients with pre-existing organ dysfunction
藥物動力學
半衰期
吸收
Completely absorbed after subcutaneous injection. Peak plasma levels occur approximately 6 hours post-dose in dogs, and 2 hours post-dose in cats. Exhibits non-linear kinetics; increasing the dose does not proportionally increase plasma concentration.
分佈
Highly bound to plasma proteins (98.5% in dogs; 99.8% in cats). The slow dissociation from these proteins is responsible for its long elimination half-life. Volume of distribution (steady-state): 0.122 ± 0.011 L/kg (dog), 0.09 ± 0.01 L/kg (cat).
代謝
Not extensively metabolized.
排除
Primarily eliminated via renal mechanisms, with the majority of the dose excreted unchanged in the urine. A small amount is excreted unchanged in the bile. Total body clearance: 0.76 ± 0.13 mL/hr/kg (dog), 0.350 ± 0.40 mL/kg/hr (cat). The drug may persist in the body for up to 65 days.
過量
Acute overdoses are generally well tolerated and relatively safe.
- Dogs: Administered SC up to 180 mg/kg (22.5X the labeled dose) showed only injection site irritation, vocalization, and transient edema (which resolved within 8-24 hours).
- Cats: Administered the same 22.5X dose showed similar injection site signs. However, 10 days post-injection, treated cats had lower mean white blood cell counts compared to controls, and one cat exhibited a small amount of bilirubinuria on day 10.
- Treatment: If massive overdose occurs or severe adverse effects are noted, treatment is symptomatic and supportive. Due to the long half-life, prolonged monitoring may be required.
可用產品
劑型
- Injectable lyophilized powder (reconstitutes to 80 mg/mL)
獸醫用
- Cefovecin Sodium (lyophilized) 800 mg (of cefovecin) per 10 mL multidose vial (80 mg/mL when reconstituted); Convenia® (Pfizer); Rx
各地核准狀態
POM-V classification. Highest priority critically important antibiotic.
POM-V classification.
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儲存與穩定性
Store the lyophilized powder and the reconstituted product in the original carton, refrigerated at 2°-8°C (36°-46°F). Protect from light. Use the entire contents of the vial within 28 days of reconstitution. The color of the solution may vary from clear to amber upon reconstitution and may darken over time; if stored properly, this color change does not adversely affect potency.
飼主須知
什麼是頭孢維星 (Convenia)？ 頭孢維星是一種在獸醫院透過注射給藥的長效抗生素。它對治療某些皮膚和軟組織感染非常有效。
寵物主人注意事項：
- 便利性： 單次注射即可提供數天至數週的抗生素治療，免去您在家每天餵食藥丸或藥水的麻煩。
- 長效持久： 注射後，此藥物會在您寵物的體內停留約 2 個月（長達 65 天）。
- 副作用： 雖然通常非常安全，但有些寵物可能會出現疲倦、食慾下降或嘔吐。由於藥物在體內停留時間長，如果您的寵物出現過敏反應或嚴重的副作用，可能需要較長時間的獸醫照護。
- 緊急處置： 如果您的寵物在接受注射後出現臉部腫脹、蕁麻疹、嚴重嘔吐、腹瀉或極度嗜睡，請立即聯繫您的獸醫師。
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