レボカルニチン / L-カルニチン
Levocarnitine
L-carnitine
別名: Carnitor · L-Carnitine · Vitamin B(T) · levocarnitinum
VetSheet 獣医チームが監修更新日 2026年4月5日エビデンスに基づく獣医学リファレンス
用量は獣医専門家向けの臨床参考資料です。必ず最新の医薬品情報および個別症例に基づいて確認してください。
動物種別用量
🌎 NA — North America🌍 EU — Europe
犬
| 適応 | 用量 | 経路 | 頻度 | 期間 | 地域 |
|---|---|---|---|---|---|
| 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
猫
| 適応 | 用量 | 経路 | 頻度 | 期間 | 地域 |
|---|---|---|---|---|---|
| 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).
用量は獣医専門家向けの臨床参考資料です。必ず最新の医薬品情報および個別症例に基づいて確認してください。
概要
レボカルニチン（L-カルニチン）は、メチオニンとリジンから生体内で合成される天然のアミノ酸誘導体であり、正常な脂肪利用とエネルギー代謝に不可欠です。
獣医学では、主に以下の補助療法として栄養補助食品として使用されます：
- 犬の拡張型心筋症（DCM）（特にコッカースパニエルやボクサー。最大90%がカルニチン欠乏症の可能性があります）。
- 猫の肝リピドーシス（肝臓の脂質代謝とクリアランスを促進します）。
- ドキソルビシン誘発性心毒性に対する保護。
- バルプロ酸毒性の補助治療。
臨床のポイント： L-異性体（レボカルニチン）のみが生物学的に活性であり有益です。D-カルニチンを含むラセミ混合物は、L-カルニチンの取り込みを競合的に阻害し、欠乏症を引き起こす可能性があるため避ける必要があります。
作用機序
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・警告
禁忌
- Use of D-carnitine or racemic (D,L) mixtures (competitively inhibits L-carnitine uptake)
有害事象
- 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.
医薬品相互作用
Patients receiving valproic acid may require higher dosages of levocarnitine due to drug-induced carnitine depletion.
監視
- Clinical efficacy (improvement in cardiac or hepatic signs)
- Periodic blood chemistries (recommended in humans, value in veterinary medicine is undetermined)
薬物動態
吸収
In humans, absorbed rapidly in the intestine via passive and active mechanisms, but overall GI bioavailability is low (about 15%).
分布
Highest levels are found in skeletal muscle. Distributed into milk.
代謝
Synthesized in vivo from methionine and lysine.
消失
Exogenously administered levocarnitine is eliminated by both renal and fecal routes. Plasma levels may be increased in patients with renal failure.
過剰投与
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.
製品
製剤
- Oral Tablets
- Oral Capsules
- Oral Solution
- Injection
- Bulk powder
ヒト用医薬品
- 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)
規制ステータス
規制データなし: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
保管・安定性
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.
飼主向け情報
投与方法：胃腸の不調（軟便や吐き気など）を軽減するため、なるべく食事と一緒に与えてください。
治療の期待：心疾患（拡張型心筋症など）の場合、このサプリメントは通常、総合的な治療計画の一部です。カルニチン療法に反応する犬の大部分は、臨床症状をコントロールするために引き続き他の処方薬を必要とします。
製品の選択：必ずL-カルニチン（レボカルニチン）を購入してください。D-カルニチンやラセミ混合物を含む製品は、体がサプリメントを利用する能力を妨げる可能性があるため避けてください。
VetSheet医薬品リファレンスは獣医専門家の臨床意思決定支援を目的としており、専門的判断または製造業者の最新医薬品情報の代替にはなりません。