左卡尼汀 / 左旋肉鹼
Levocarnitine
L-carnitine
別名: Carnitor · L-Carnitine · Vitamin B(T) · levocarnitinum
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
劑量為合格獸醫專業人員的臨床參考。請務必對照最新仿單及個別病患確認。
各物種劑量
🌎 NA — North America🌍 EU — Europe
狗
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Trial for treating canine dilated cardiomyopathy (large or giant breed dog) | 2 grams PO q8-12h | PO | q8-12h | — | 🌎 NA |
| Adjunctive therapy of dilated cardiomyopathy in American Cocker spaniels | 1 gram PO q8-12h | PO | q8-12h | — | 🌎 NA |
| Severe myocardial failure in Boxers | 2-3 grams PO q12h | PO | q12h | 2-4 months | 🌎 NA |
| Adjunctive treatment of American cocker spaniels with dilated cardiomyopathy | 1 g PO q12h | PO | q12h | — | 🌎 NA |
| Dilated cardiomyopathy in American Cocker spaniels | 1 g PO q8h | PO | q8h | — | 🌎 NA |
| Dilated cardiomyopathy in Boxer dogs | 2 g PO q8h | PO | q8h | — | 🌎 NA |
| Documented systemic carnitine deficiency | 50-100 mg/kg PO q8h | PO | q8h | — | 🌎 NA |
| Myocardial carnitine deficiency only | 200 mg/kg PO q8h | PO | q8h | — | 🌎 NA |
- Trial for treating canine dilated cardiomyopathy (large or giant breed dog): Approximately 1 teaspoonful of pure powder
- Adjunctive therapy of dilated cardiomyopathy in American Cocker spaniels: Give with taurine. Approximately 1/2 teaspoonful.
- Severe myocardial failure in Boxers: To determine if they respond
- Adjunctive treatment of American cocker spaniels with dilated cardiomyopathy: Give with taurine 500 mg q12h PO
貓
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Adjunctive dietary therapy in cats with severe hepatic lipidosis | 250 mg PO once daily | PO | q24h | — | 🌎 NA |
| Supplementation in cats with liver disease | 250-500 mg/day | PO | q24h | — | 🌎 NA |
- Adjunctive dietary therapy in cats with severe hepatic lipidosis: Use Carnitor; also supplement with taurine (250 mg once to twice daily), Vitamin E (10 Units/kg/day), water soluble vitamins and determine B12 status (treat while awaiting data at 1 mg/cat SC).
劑量為合格獸醫專業人員的臨床參考。請務必對照最新仿單及個別病患確認。
概覽
左卡尼汀（L-肉鹼）是一種天然存在的氨基酸衍生物，由蛋氨酸和賴氨酸在體內合成，對正常的脂肪利用和能量代謝至關重要。
在獸醫學中，它主要作為營養補充劑，用於輔助治療：
- 犬擴張性心肌病 (DCM)（特別是可卡犬和拳師犬，高達90%可能缺乏肉鹼）。
- 貓脂肪肝 (Feline Hepatic Lipidosis)，促進肝臟脂質代謝和清除。
- 預防阿黴素 (Doxorubicin) 引起的心臟毒性。
- 輔助治療丙戊酸 (Valproic acid) 中毒。
臨床要點： 只有L-異構體（左卡尼汀）具有生物活性和益處。必須避免使用含有D-肉鹼的外消旋混合物，因為它們會競爭性抑制L-肉鹼的吸收並可能導致缺乏症。
作用機轉
Levocarnitine acts as an essential cofactor for the carnitine palmitoyltransferase (CPT) system.
It binds to long-chain free fatty acids in the cytosol, forming acylcarnitine, which is then transported across the inner mitochondrial membrane.
Inside the mitochondria → the fatty acids undergo beta-oxidation → generating ATP (cellular energy). This mechanism is particularly crucial for the myocardium, which relies heavily on fatty acid oxidation for energy, and for the liver during states of lipid mobilization (e.g., feline hepatic lipidosis).
安全性與警告
禁忌症
- Use of D-carnitine or racemic (D,L) mixtures (competitively inhibits L-carnitine uptake)
不良反應
- Gastrointestinal upset (loose stools, diarrhea, nausea, vomiting) - usually mild and dose-dependent
- Increased body odor (reported in human patients)
注意事項
Use only the Levo- (L-) forms of carnitine. Products labeled as 'Vitamin BT' may contain both D and L racemic forms; the D-form competitively inhibits L-uptake and can cause a deficiency. Generally considered safe to use during pregnancy (FDA Category B in humans), though documented safety in pregnant animals has not been definitively established.
藥物交互作用
Patients receiving valproic acid may require higher dosages of levocarnitine due to drug-induced carnitine depletion.
監測
- Clinical efficacy (improvement in cardiac or hepatic signs)
- Periodic blood chemistries (recommended in humans, value in veterinary medicine is undetermined)
藥物動力學
吸收
In humans, absorbed rapidly in the intestine via passive and active mechanisms, but overall GI bioavailability is low (about 15%).
分佈
Highest levels are found in skeletal muscle. Distributed into milk.
代謝
Synthesized in vivo from methionine and lysine.
排除
Exogenously administered levocarnitine is eliminated by both renal and fecal routes. Plasma levels may be increased in patients with renal failure.
過量
Levocarnitine is a relatively safe drug.
- Minor overdoses: Need only to be monitored.
- Massive overdoses: Consider gut emptying (emesis or gastric lavage). Refer to a veterinary poison control center for more information.
可用產品
劑型
- Oral Tablets
- Oral Capsules
- Oral Solution
- Injection
- Bulk powder
人用標示
- Levocarnitine Oral Tablets: 330 mg & 500 mg (Carnitor, generic)
- Levocarnitine Oral Capsules: 250 mg (generic)
- Levocarnitine Oral Solution: 100 mg/mL (Carnitor, generic)
- Levocarnitine Injection: 200 mg/mL in single-dose vials & amps (Carnitor, generic)
各地核准狀態
暫無法規資料: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
儲存與穩定性
Capsules, tablets, and powder should be stored in well-closed containers at room temperature. Oral solution should be kept in tight containers at room temperature. Injection should be stored at room temperature in the original carton; discard any unused portion after opening, as the injection contains no preservative.
飼主須知
給藥方式：請盡量與食物一起餵食，以減少腸胃不適（如軟便或噁心）的可能性。
治療預期：對於心臟疾病（如擴張性心肌病），此補充劑通常是綜合治療計畫的一部分。大多數對肉鹼治療有反應的犬隻，仍需要服用其他處方藥物來控制臨床症狀。
產品選擇：請確保購買的是L-肉鹼 (L-carnitine)。避免使用含有D-肉鹼或外消旋混合物的產品，因為它們會干擾身體吸收和利用該補充劑的能力。
VetSheet 藥物參考供合格獸醫專業人員作臨床決策輔助之用，不能取代專業判斷或廠商最新仿單。