阿托伐醌
Atovaquone
hydroxy-1,4-naphthoquinone
別名: Mepron · Malanil · Wellvone · BW-556C · Atovacuona · Atovakvoni · Atovaquonnum
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 |
|---|---|---|---|---|---|
| Babesia gibsoni (Asian genotype) infections | 13.3 mg/kg PO q8h | PO | q8h | 10 days | 🌎 NA |
| Pneumocystosis | 15 mg/kg PO once daily | PO | q24h | 3 weeks | 🌎 NA |
- Babesia gibsoni (Asian genotype) infections: Give with Azithromycin 10 mg/kg PO once daily. Reserve immunosuppressive therapy for cases that are not rapidly responding (3-5 days) to anti-protozoal therapy.
- Pneumocystosis: Considered second line therapy after potentiated sulfonamides.
貓
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Cytauxzoonosis (Cytauxzoon felis) | 15 mg/kg PO q8h | PO | q8h | Not specified | 🌎 NA |
- Cytauxzoonosis (Cytauxzoon felis): Give with azithromycin 10 mg/kg PO q24h. All cases were treated with IV fluids and most received heparin.
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
阿托伐醌 (Atovaquone) 是一種高脂溶性的合成羥基萘醌類抗原蟲藥物。在獸醫學中，它為治療某些難治的蜱媒原蟲感染帶來了革命性的突破。
主要臨床用途：
- 犬吉氏巴貝斯蟲 (Babesia gibsoni) 感染： 與阿奇黴素 (Azithromycin) 產生協同作用。吉氏巴貝斯蟲是一種小型焦蟲，通常對傳統療法（如雙脒苯脲）具有抗藥性。阿托伐醌/阿奇黴素組合是目前的治療首選。
- 貓細胞簇蟲 (Cytauxzoon felis) 感染： 與阿奇黴素合併使用。貓細胞簇蟲病是一種高致命性的蜱媒疾病；此藥物組合配合積極的支持性療法（靜脈輸液、肝素），已顯著提高患貓的存活率。
- 犬肺孢子蟲病 (Pneumocystosis)： 當無法使用增效磺胺類藥物或無效時，作為肺孢子蟲肺炎的二線療法。
臨床要點： 阿托伐醌單獨使用或與阿奇黴素合併使用時通常耐受性良好，但價格相當昂貴。人類複方藥物 Malarone®（阿托伐醌/氯胍）絕對不可替代用於犬隻，因為其中的氯胍 (proguanil) 成分會引起嚴重的胃腸道毒性。
作用機制
Atovaquone acts as a selective and potent inhibitor of the protozoan mitochondrial electron transport chain.
- It acts as a structural analogue of ubiquinone (Coenzyme Q).
- It binds to the ubiquinol oxidation pocket of the cytochrome bc1 complex (Complex III) in the protozoan inner mitochondrial membrane.
- This binding blocks electron transfer → collapses the mitochondrial membrane potential → halts the function of dihydroorotate dehydrogenase, an enzyme critically dependent on electron transport.
- Inhibition of this enzyme prevents de novo pyrimidine synthesis. Because these specific protozoa lack the ability to salvage preformed pyrimidines from their host, they cannot synthesize DNA or RNA, leading to parasite death.
安全性與警告
禁忌症
- Patients with a known hypersensitivity to atovaquone
- Patients with severe malabsorption syndromes
- Patients who cannot tolerate oral intake or cannot take the drug with a high-fat meal
不良反應
- Gastrointestinal upset (nausea, vomiting, diarrhea)
- Rashes or hypersensitivity reactions
- Elevated liver enzymes
- CNS effects (headache, dizziness in humans)
- Fever
- Neutropenia and anemia (rare)
注意事項
Administration Warning: The drug is highly lipophilic and has poor bioavailability on an empty stomach. It must be administered with a high-fat meal to ensure adequate systemic absorption.
Toxicity Warning: Do not use the human combination product Malarone® (atovaquone and proguanil) in dogs due to severe gastrointestinal adverse effects associated with proguanil.
Pregnancy/Nursing: FDA Category C. Studies in rabbits showed increased maternal and fetal toxicity (decreased fetal growth, early resorption). Use during pregnancy only if the potential benefit justifies the risk. It is excreted in milk in rats, though it is unlikely to pose significant risk to nursing puppies.
藥物相互作用
Can decrease atovaquone plasma concentrations
Can decrease atovaquone plasma concentrations
Can decrease atovaquone plasma concentrations
監測
- Clinical signs of efficacy (resolution of fever, lethargy, anemia)
- Serial CBCs to monitor anemia and platelet counts
- BUN, liver enzymes, and serum potassium (hypokalemia) in severe cases
- PCR testing at 60 days and 90 days post-therapy to confirm 'clearing' of B. gibsoni
藥物動力學
吸收
Bioavailability is highly dependent on food. In humans, fasting bioavailability is 23-47%, but the presence of food (particularly high in fat) increases bioavailability significantly (2+ fold).
分佈
Highly bound to plasma proteins (99.9%). Levels in the CSF are approximately 1% of those found in plasma.
代謝
There may be limited hepatic metabolism.
排除
The bulk of absorbed drug is eventually eliminated unchanged in the feces. Enterohepatic recycling occurs.
過量
Limited information is available for any species regarding acute toxicity. Minimum toxic doses have not been established; laboratory animals have tolerated massive doses up to 31.5 grams without lethal effect.
If an overdose occurs, treatment should be symptomatic and supportive. Due to high protein binding, dialysis is unlikely to be effective.
可用產品
劑型
- Oral suspension (150 mg/mL)
人用標示
- Atovaquone Oral Suspension: 150 mg/mL in 210 mL bottles; citrus flavor; Mepron® (GlaxoWellcome); (Rx)
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
The commercially available oral suspension should be stored at room temperature (15-25°C) in tight containers and protected from bright light; do not freeze.
飼主須知
重要給藥指示：
- 與高脂食物同服： 此藥物必須與高脂肪食物（例如：少許冰淇淋、鮪魚油、奶油或肉類脂肪）一起餵食，才能被寵物的身體充分吸收。若缺乏脂肪，藥物將無法發揮效用。
- 使用前搖勻： 每次抽取劑量前，請輕輕搖勻藥瓶。
- 儲存方式： 請將藥水儲存於室溫下，避開強光照射。請勿冷凍。
注意事項：
- 此藥物通常耐受性良好，但因為它是獸醫學中較新的療法，我們仍在持續了解其所有潛在的副作用。
- 如果您的寵物出現皮膚紅疹，或有嚴重且持續的嘔吐或腹瀉，請立即聯繫您的獸醫師。
- 注意： 此藥水呈鮮黃色，可能會使布料或物體表面染色，請小心處理。
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