阿莫西林
Amoxicillin
Amoxicillin trihydrate
別名: Amoxil · Amoxi-Tabs · Amoxi-Drop · Amoxi-Mast · Trimox · Moxatag · Amoxibactin · Amoxycare · Amoxypen · Betamox · Bimoxyl · Clamoxyl · amoxycillin · p-hydroxyampicillin · BRL 2333
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
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。
各物種劑量
🌎 NA — North America🌍 EU — Europe
狗
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Gram-positive infections | 10 mg/kg PO, IM, SC twice daily for at least 2 days after symptoms subside. | PO, IM, SC | q12h | At least 2 days after symptoms subside | 🌎 NA |
| Gram-negative infections | 20 mg/kg PO three times daily or IM, SC twice daily for at least 2 days after symptoms subside | PO, IM, SC | q8h (PO) or q12h (IM, SC) | At least 2 days after symptoms subside | 🌎 NA |
| Susceptible UTI's | 10-20 mg/kg PO q12h for 5-7 days. | PO | q12h | 5-7 days | 🌎 NA |
| Susceptible systemic infections (bacteremia/sepsis) | 22-30 mg/kg IV , IM, SC q8h for 7 days. | IV, IM, SC | q8h | 7 days | 🌎 NA |
| Susceptible orthopedic infections | 22-30 mg/kg IV , IM, SC, or PO q6-8h for 7-10 days. | IV, IM, SC, PO | q6-8h | 7-10 days | 🌎 NA |
| Lyme disease | 22 mg/kg PO q12h for 21-28 days | PO | q12h | 21-28 days | 🌎 NA |
| Susceptible urinary tract infections | 11 mg/kg PO q8h. | PO | q8h | — | 🌎 NA |
| Preventative therapy for repeated (>2 per 6 months) urinary tract Gram-positive bacterial infections | 20 mg/kg PO once daily before bedtime after the dog has urinated. | PO | q24h | — | 🌎 NA |
| Susceptible bacterial infections | 7 mg/kg | IM | q24h | — | 🌍 EU |
| Susceptible bacterial infections (depot preparations) | 15 mg/kg | IM | q48h | — | 🌍 EU |
| Susceptible bacterial infections | 10 mg/kg | PO | q8-12h | — | 🌍 EU |
| Bacterial cystitis | 11-15 mg/kg | PO | q8h | — | 🌍 EU |
- Preventative therapy for repeated (>2 per 6 months) urinary tract Gram-positive bacterial infections: Use only after effective treatment completed using full therapeutic doses.
- Susceptible bacterial infections (depot preparations): For depot preparations only
- Susceptible bacterial infections: Dose chosen will depend on site of infection, causal organism and severity of the disease.
- Bacterial cystitis: Evidence of a need for clavulanic acid is lacking even in infections with beta-lactamase producing bacteria.
貓
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Gram-positive infections | 10 mg/kg PO, IM, SC twice daily for at least 2 days after symptoms subside. | PO, IM, SC | q12h | At least 2 days after symptoms subside | 🌎 NA |
| Gram-negative infections | 20 mg/kg PO three times daily or IM, SC twice daily for at least 2 days after symptoms subside | PO, IM, SC | q8h (PO) or q12h (IM, SC) | At least 2 days after symptoms subside | 🌎 NA |
| Susceptible UTI's and soft tissue infections | 50 mg (total dose per cat) or 11-22 mg/kg PO once daily for 5-7 days. | PO | q24h | 5-7 days | 🌎 NA |
| Sepsis | 10-20 mg/kg IV , SC, or PO q12h for as long as necessary. | IV, SC, PO | q12h | As long as necessary | 🌎 NA |
| C. perfringens, bacterial overgrowth (GI) | 22 mg/kg PO once daily for 5 days | PO | q24h | 5 days | 🌎 NA |
| C. perfringens enterotoxicosis | 11-22 mg/kg PO two to three times daily for 7 days | PO | q8-12h | 7 days | 🌎 NA |
| H. pylori infections (triple therapy) | amoxicillin 20 mg/kg PO twice daily for 14 days; metronidazole 10-15 mg/kg PO twice daily; clarithromycin 7.5 mg/kg PO twice daily | PO | q12h | 14 days | 🌎 NA |
| Susceptible bacterial infections | 7 mg/kg | IM | q24h | — | 🌍 EU |
| Susceptible bacterial infections (depot preparations) | 15 mg/kg | IM | q48h | — | 🌍 EU |
| Susceptible bacterial infections | 10 mg/kg | PO | q8-12h | — | 🌍 EU |
| Bacterial cystitis | 11-15 mg/kg | PO | q8h | — | 🌍 EU |
- Sepsis: Generally treat for at least 2 days after all signs of infection are gone.
- H. pylori infections (triple therapy): Used in combination with metronidazole and clarithromycin.
- Susceptible bacterial infections (depot preparations): For depot preparations only
- Susceptible bacterial infections: Dose chosen will depend on site of infection, causal organism and severity of the disease.
- Bacterial cystitis: Evidence of a need for clavulanic acid is lacking even in infections with beta-lactamase producing bacteria.
小型哺乳類
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Susceptible infections (Hedgehogs) | 15 mg/kg IM or PO q12h | IM, PO | q12h | — | 🌎 NA |
- Susceptible infections (Hedgehogs): See contraindications regarding use in rabbits/rodents.
雪貂
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Eliminating Helicobacter gastritis infections (triple therapy) | Metronidazole 22 mg/kg, amoxicillin 22 mg/kg and bismuth subsalicylate (original Pepto-Bismol ®) 17.6 mg/kg PO. Give each 3 times daily for 3-4 weeks. | PO | q8h | 3-4 weeks | 🌎 NA |
| Eliminating Helicobacter gastritis infections (triple therapy) | Metronidazole 20 mg/kg PO q12h, amoxicillin 20 mg/kg PO q12h and bismuth subsalicylate 17.5 mg/kg PO q8h. Give 21 days. | PO | q12h | 21 days | 🌎 NA |
| Susceptible infections | 10-35 mg/kg PO or SC twice daily | PO, SC | q12h | — | 🌎 NA |
- Eliminating Helicobacter gastritis infections (triple therapy): Sucralfate and famotidine are also used. Fluids and assisted feeding should be continued.
鳥
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Susceptible infections | 125 mg/kg q12h PO. Mix oral solution to double strength to a final concentration of 125 mg/mL. | PO | q12h | — | 🌎 NA |
| Susceptible infections | 100 mg/kg q8h, IM, SC, PO | IM, SC, PO | q8h | — | 🌎 NA |
| Susceptible infections (Ratites) | 15-22 mg/kg PO twice daily; in drinking water: 250 mg/gallon for 3-5 days | PO, drinking water | q12h / continuous | 3-5 days | 🌎 NA |
爬蟲類
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Susceptible infections (all species) | 22 mg/kg PO q12-24h | PO | q12-24h | — | 🌎 NA |
- Susceptible infections (all species): Not very useful unless used in combination with aminoglycosides
馬
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Respiratory infections | 20-30 mg/kg PO q6h | PO | q6h | — | 🌎 NA |
| Susceptible infections (Foals - Amoxicillin Sodium) | 15-30 mg/kg IV or IM q6-8h | IV, IM | q6-8h | — | 🌎 NA |
| Susceptible infections (Foals - Amoxicillin trihydrate suspension) | 25-40 mg/kg PO q8h | PO | q8h | — | 🌎 NA |
| Susceptible infections (Foals - Amoxicillin/clavulanate) | 15-25 mg/kg IV q6-8h | IV | q6-8h | — | 🌎 NA |
牛
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Susceptible infections | 6-10 mg/kg SC or IM q24h | SC, IM | q24h | — | 🌎 NA |
| Respiratory infections | 11 mg/kg IM or SC q12h | IM, SC | q12h | — | 🌎 NA |
| Susceptible infections (Calves - Amoxicillin trihydrate) | 7 mg/kg PO q8-12h | PO | q8-12h | — | 🌎 NA |
- Susceptible infections: Withdrawal time = 30 days
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（Amoxicillin）是獸醫學中廣泛開立的廣效氨基青黴素抗生素，用於治療多種細菌感染。
主要藥理特徵包括：
- 抗菌譜：對許多革蘭氏陽性需氧菌、部分革蘭氏陰性需氧菌（如大腸桿菌、克雷伯氏菌、嗜血桿菌）及許多絕對厭氧菌（包含梭狀芽孢桿菌屬）有效。
- 對β-內醯胺酶的敏感性：與氨苄西林（Ampicillin）相同，會被產生β-內醯胺酶的細菌（如金黃色葡萄球菌）去活化。臨床上常與克拉維酸（Clavulanate）結合使用以克服此抗藥性。
- 臨床應用：被認為是貓膿瘍、敏感性泌尿道感染（UTIs）及軟組織感染的第一線經驗性治療首選。
- 藥代動力學優勢：與氨苄西林相比，阿莫西林在單胃動物中的口服生物利用度顯著較佳，在同等劑量下可達到1.5至3倍的血清濃度。
作用機制
Amoxicillin is a time-dependent, bactericidal antibiotic that disrupts bacterial cell wall synthesis.
- Mechanism: The beta-lactam ring mimics the D-alanyl-D-alanine terminal of the peptidoglycan precursor.
- Pathway: Amoxicillin binds to specific penicillin-binding proteins (PBPs) (such as transpeptidases, carboxypeptidases, and endopeptidases) located on the inner surface of the bacterial cell membrane → inhibits the cross-linking of mucopeptide (peptidoglycan) chains → compromises the structural integrity of the cell wall → creates an osmotically unstable spheroplast → results in cell lysis and death.
- Efficacy: It is most effective against actively dividing and growing bacteria.
安全性與警告
禁忌症
- Patients with a history of hypersensitivity to penicillins
- Oral administration in 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)
- Antibiotic-associated diarrhea and gut flora alteration
- Hypersensitivity reactions (rashes, fever, anaphylaxis)
- Eosinophilia, neutropenia, agranulocytosis, thrombocytopenia, leukopenia, anemias
- Lymphadenopathy
- Neurotoxicity (e.g., ataxia) at very high doses or prolonged use
- Elevated liver enzymes (rare)
- Tachypnea, dyspnea, edema, and tachycardia (reported in dogs)
注意事項
Species Warning: Never administer amoxicillin (or other penicillins) orally to rabbits, guinea pigs, chinchillas, or hamsters, as it can cause severe, often fatal, clostridial enterotoxemia.
- Cross-Reactivity: Use with caution in patients with documented hypersensitivity to other beta-lactam antibiotics (e.g., cephalosporins, carbapenems).
- Pregnancy: Crosses the placenta. Categorized as FDA Category B (human) and Class A (veterinary - probably safe), but should be used only when potential benefits outweigh risks.
- Laboratory Tests: May cause false-positive urine glucose determinations when using cupric sulfate solutions (e.g., Clinitest).
藥物相互作用
Potential in vitro antagonism; concurrent use has historically been discouraged, though clinical significance is debated.
Amoxicillin may decrease the renal excretion of methotrexate, leading to increased levels and potential toxicity.
Competitively blocks the tubular secretion of penicillins, increasing serum levels and prolonging serum half-life.
In vitro inactivation of aminoglycosides by beta-lactams; may falsely decrease aminoglycoside serum concentrations if samples are stored prior to analysis.
Potential antagonism of bactericidal activity (bacteriostatic vs bactericidal)
Potential antagonism of bactericidal activity
Potential antagonism of bactericidal activity
Inactivation of aminoglycoside if mixed in the same syringe
Synergistic antimicrobial effect when used concurrently
監測
- Clinical efficacy (resolution of infection signs)
- Adverse effects (GI upset, signs of hypersensitivity)
藥物動力學
半衰期
吸收
Relatively stable in gastric acid. About 74-92% absorbed orally in monogastric animals. Food decreases the rate but not the extent of absorption. Serum levels are generally 1.5-3 times greater than ampicillin after equivalent oral doses.
分佈
Volume of distribution is ~0.2 L/kg in dogs. Widely distributed to tissues including liver, lungs, muscle, bile, and ascitic/pleural/synovial fluids. Crosses into CSF when meninges are inflamed (10-60% of serum levels). Crosses the placenta. Protein binding is ~13% in dogs.
代謝
Some of the drug is metabolized by hydrolysis to inactive penicilloic acids.
排除
Eliminated primarily through renal mechanisms, principally by tubular secretion. Clearance is reportedly 1.9 mL/kg/min in dogs.
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 compromised renal function, have induced CNS effects (e.g., seizures, ataxia). Treatment is generally supportive and symptomatic.
可用產品
劑型
- Oral tablets
- Oral chewable tablets
- Oral capsules
- Powder for oral suspension
- Intramammary infusion
獸醫用
- Amoxicillin Oral Tablets: 50 mg, 100 mg, 150 mg, 200 mg, & 400 mg (Amoxi-Tabs®)
- Amoxicillin Powder for Oral Suspension: 50 mg/mL after reconstitution (Amoxi-Drop®)
- Amoxicillin Intramammary Infusion: 62.5 mg/syringe (Amoxi-Mast®)
人用標示
- Amoxicillin Oral Tablets (chewable): 125 mg, 200 mg, 250 mg, & 400 mg (Amoxil®)
- Amoxicillin Oral Tablets: 500 mg & 875 mg (Amoxil®)
- Amoxicillin Oral Capsules: 250 mg & 500 mg (Amoxil®)
- Amoxicillin Powder for Oral Suspension: 200 mg/5 mL, 250 mg/5 mL, 400 mg/5 mL (Amoxil®, Trimox®)
- Amoxicillin Oral Extended-Release Tablets: 775 mg (Moxatag®)
各地核准狀態
暫無法規資料: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
儲存與穩定性
Capsules, tablets, and powder for oral suspension should be stored at room temperature (15-30°C) in tight containers. After reconstitution, the oral suspension should preferably be refrigerated (though not absolutely necessary) and any unused product discarded after 14 days.
飼主須知
- 給藥方式：阿莫西林可與食物一起或空腹給予。但如果您的寵物出現腸胃不適（嘔吐或食慾不振），與食物一起餵食可能會有所幫助。
- 儲存方式：如果您使用的是口服懸浮液，最好將其冷藏，但室溫保存亦可。配製後超過14天的未用完藥液請務必丟棄。
- 完成療程：即使您的寵物看起來已經完全康復，也請務必按照獸醫師的指示完成整個療程。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，或者您注意到過敏反應的跡象（如面部腫脹、蕁麻疹或呼吸困難），請立即聯繫您的獸醫師。
- 物種警告：絕對不要將此藥物分享給兔子、天竺鼠或倉鼠等小型寵物，因為這對牠們可能是致命的。
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