阿莫西林/克拉維酸
Amoxicillin/Clavulanate Potassium
Amoxicillin trihydrate and Clavulanate potassium
別名: Clavamox · Augmentin · Amoclan · amoxycillin · p-hydroxyampicillin · BRL 2333 · clavulanic acid · BRL-14151K · kalii clavulanas
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Sporadic bacterial cystitis (extra-label)
- q8-12h
NA
必須同時考慮的臨床上下文 (3)
- NOTE: All dosages listed are for combined quantities of both drugs (unless otherwise noted).
- ■ This medicine can be given with or without food, but gastrointestinal side effects might be prevented if this medicine is given with food.
- Clavulanate products should be stored at temperatures below 25°C (77°F), and some tablet formulations specify storage at 20°C to 25°C (68°F-77°F). Potassium clavulanate is very susceptible to moisture and should be protected from excessive humidity.
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
阿莫西林/克拉維酸（獸醫界常用商品名為 Clavamox®）是一種高效、廣效的增效氨基青黴素抗生素。
- 擴大抗菌譜： 添加了β-內醯胺酶抑制劑（克拉維酸），可保護阿莫西林免受酵素破壞，顯著擴大其抗菌範圍，涵蓋許多產生β-內醯胺酶的細菌（如葡萄球菌、大腸桿菌）。
- 臨床應用： 獲 FDA 批准用於犬貓的泌尿道感染 (UTI)、皮膚與軟組織感染及牙周病。
- 經驗性首選： 是治療母犬細菌性膀胱炎的極佳第一線經驗性用藥；若與氟喹諾酮類藥物併用，也適用於肝膽道感染。
- 限制： 通常對綠膿桿菌 (Pseudomonas aeruginosa) 或腸桿菌屬 (Enterobacter) 無效，因為這些細菌常產生克拉維酸無法抑制的第一型頭孢菌素酶。
作用機制
Amoxicillin is a time-dependent, bactericidal antibiotic that binds to Penicillin-Binding Proteins (PBPs) → inhibits bacterial cell wall peptidoglycan cross-linking → compromises cell wall integrity → cell lysis and death.
Clavulanic acid acts as a "suicide inhibitor" by competitively and irreversibly binding to beta-lactamase enzymes (types II, III, IV, V, and staphylococcal penicillinases) → prevents the enzymatic destruction of amoxicillin → restores and expands the antimicrobial spectrum against resistant organisms.
Note: There is little synergistic activity against organisms already susceptible to amoxicillin alone.
安全性與警告
禁忌症
- Patients with a history of hypersensitivity to penicillins
- Small hindgut fermenters (rabbits, guinea pigs, chinchillas, hamsters) due to risk of fatal clostridial enterotoxemia
- Oral administration in patients with septicemia, shock, or grave illness (due to delayed/diminished GI absorption)
不良反應
- Gastrointestinal upset (anorexia, vomiting, diarrhea)
- Hypersensitivity reactions (rashes, fever, eosinophilia, anaphylaxis)
- Antibiotic-associated diarrhea and superinfections (due to altered gut flora)
- Neurotoxicity (e.g., ataxia in dogs) at very high doses or prolonged use
- Elevated liver enzymes (rare)
- Tachypnea, dyspnea, edema, and tachycardia (rarely reported in dogs)
注意事項
WARNING FOR EXOTIC PETS: Do not administer penicillins to rabbits, guinea pigs, chinchillas, or hamsters, as severe enteritis and fatal clostridial enterotoxemia may occur.
- Cross-Reactivity: Use cautiously in patients with documented hypersensitivity to other beta-lactam antibiotics (e.g., cephalosporins, carbapenems).
- Critically Ill Patients: Avoid oral administration in patients in shock or with septicemia due to unreliable gastrointestinal absorption.
- Laboratory Interference: May cause false-positive urine glucose determinations when using cupric sulfate solutions (e.g., Clinitest®).
藥物相互作用
Theoretical in vitro antagonism; clinical importance is currently in doubt but historically not recommended to combine.
Amoxicillin may decrease the renal excretion of methotrexate, causing increased levels and potential toxic effects.
Competitively blocks the tubular secretion of most penicillins, thereby increasing serum levels and serum half-lives.
In vitro inactivation can occur if mixed together; serum concentrations of aminoglycosides may be falsely decreased if stored prior to analysis.
監測
- Clinical efficacy (resolution of infection signs)
- Adverse gastrointestinal signs (vomiting, diarrhea, anorexia)
藥物動力學
半衰期
吸收
Clavulanate potassium is relatively stable in the presence of gastric acid and is readily absorbed. Peak levels occur about 1 hour after dosing.
分佈
Clavulanic acid has an apparent volume of distribution of 0.32 L/kg in dogs. Distributes (with amoxicillin) into lungs, pleural fluid, and peritoneal fluid. Low concentrations in saliva, sputum, and uninflamed CSF. Readily crosses the placenta and is found in milk in low concentrations. 13% bound to proteins in dog serum.
代謝
Clavulanic acid is extensively metabolized in the dog primarily to 1-amino-4-hydroxybutan-2-one.
排除
Excreted unchanged in the urine via glomerular filtration. In dogs, 34-52% is excreted in urine, 25-27% in feces, and 16-33% into respired air.
過量
Acute oral penicillin overdoses are unlikely to cause significant problems other than gastrointestinal distress (vomiting, diarrhea, anorexia).
In humans, very high dosages of parenteral penicillins, especially in patients with underlying renal disease, have induced Central Nervous System (CNS) effects. Treatment of oral overdose should be supportive and symptomatic.
可用產品
劑型
- Oral tablets
- Chewable tablets
- Powder for oral suspension
獸醫用
- Oral Tablets (4:1 ratio): 62.5 mg (50 mg amoxicillin/12.5 mg clavulanic acid), 125 mg, 250 mg, 375 mg (Clavamox Tablets®)
- Powder for Oral Suspension: 50 mg amoxicillin/12.5 mg clavulanic acid per mL in 15 mL dropper bottles (Clavamox Drops®)
人用標示
- Tablets: 250 mg/125 mg, 500 mg/125 mg, 875 mg/125 mg (Augmentin®)
- Chewable Tablets: 125 mg/31.25 mg, 200 mg/28.5 mg, 250 mg/62.5 mg, 400 mg/57 mg (Augmentin®)
- Powder for Oral Suspension: Various strengths including 125 mg/31.25 mg per 5 mL, up to 600 mg/42.9 mg per 5 mL (Augmentin®, Amoclan®)
各地核准狀態
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儲存與穩定性
Store clavulanate products at temperatures less than 24°C (75°F) in tight containers, protected from excessive humidity. After reconstitution, veterinary oral suspensions are stable for 10 days when refrigerated (discard unused portions after 10 days). If kept at room temperature, suspensions are stable for only 48 hours.
飼主須知
- 給藥方式： 此藥物可隨餐或空腹給予。如果您的寵物出現腸胃不適（嘔吐或食慾不振），與少量食物或零食一起餵食可幫助緩解。
- 藥水保存： 若使用口服懸浮液（藥水），最好冷藏保存。配製後超過 10 天的未用完藥水請丟棄，因為它會失去效力。
- 完成療程： 即使您的寵物看起來已經完全康復，也請務必按照獸醫的指示完成整個處方療程。提早停藥可能會導致細菌產生抗藥性。
- 副作用： 可能會出現輕微的腹瀉或嘔吐。如果這些症狀變得嚴重，或者您的寵物停止進食，請聯繫您的獸醫。
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