多拉菌素
Doramectin
25-cyclohexyl-5-O-demethyl-25-de(1-methylpropyl)avermectin A1a
別名: Dectomax · UK-67994
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 |
|---|---|---|---|---|---|
| Treatment of generalized demodicosis | 600 micrograms/kg | PO | once daily | Until 60 days without improvement | 🌎 NA |
| Treatment of generalized demodicosis | 600 micrograms/kg (0.6 mg/kg) | SC | once per week | — | 🌎 NA |
| Treatment of benign nodules secondary to S. lupi | 400 micrograms/kg | SC | once at two week intervals | once | 🌎 NA |
- Treatment of generalized demodicosis: Extra-label. If improvement is not seen after 60 days, an alternative therapy should be used.
- Treatment of generalized demodicosis: Extra-label. Get informed consent from owner.
- Treatment of benign nodules secondary to S. lupi: May use milbemycin in MDR-1 sensitive breeds.
貓
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Feline demodicosis (D. cati, D. gatoi) | 600 micrograms/kg (0.6 mg/kg) | SC | once per week | — | 🌎 NA |
- Feline demodicosis (D. cati, D. gatoi): Extra-label. Get informed consent from owner. Alternative treatments include Lime sulfur dips or amitraz.
小型哺乳類
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| P. cuniculi infestations (Rabbits) | 200 micrograms/kg | IM | once | once | 🌎 NA |
牛
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Labeled indications (Injectable) | 200 micrograms/kg (1 mL per 110 lb. body weight) | SC/IM | once | — | 🌎 NA |
| Labeled indications (Pour-on) | 500 micrograms/kg (1 mL per 22 lb. body weight) | topical | once | — | 🌎 NA |
- Labeled indications (Injectable): Beef Quality Assurance guidelines recommend SC administration as the preferred route.
- Labeled indications (Pour-on): Administer topically along the mid-line of the back in a narrow strip between the withers and tailhead.
豬
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Labeled indications | 300 micrograms/kg (1 mL per 75 lb. body weight) | IM | once | — | 🌎 NA |
- Labeled indications: Intramuscular injections should be administered into the muscular region of the neck.
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
多拉菌素 (Doramectin) 是一種屬於阿維菌素 (avermectin) 類的大環內酯類抗寄生蟲藥物。
- 經濟動物用途：FDA 核准用於牛和豬的注射液及外用澆潑劑，可治療多種胃腸道線蟲、肺蟲、眼蟲、牛皮蠅蛆、蝨子和疥蟎。
- 伴侶動物用途：在犬貓主要作為標示外使用 (extra-label)，用於治療全身性毛囊蟲症和犬食道蟲症 (spirocercosis)。
臨床要點：雖然非常有效，但其在小動物的使用完全屬於標示外，且具有嚴重的神經毒性風險，特別是在帶有 MDR1 (ABCB1) 基因突變的牧羊犬品種中。
作用機轉
Doramectin exerts its antiparasitic effect by binding to glutamate-gated chloride channels found in invertebrate nerve and muscle cells.
- Mechanism: Binding → increases membrane permeability to chloride ions → cellular hyperpolarization → flaccid paralysis and death of the parasite.
- It also enhances the release of gamma-aminobutyric acid (GABA) at presynaptic neurons, further inhibiting nerve transmission.
- Mammalian Safety: Mammals lack glutamate-gated chloride channels, and avermectins typically do not cross the intact mammalian blood-brain barrier (where GABA receptors reside) due to the P-glycoprotein efflux pump. Toxicity occurs when this pump is deficient (e.g., MDR1 mutation) or overwhelmed by massive overdoses.
安全性與警告
禁忌症
- Dogs with MDR1-allele mutations (relative/absolute depending on dose)
- Female dairy cattle 20 months of age or older
- Calves to be processed for veal
不良反應
- Injection site blemishes (IM administration)
- Pupil dilation (mydriasis) in dogs
- Lethargy
- Blindness
- Coma (especially in MDR1-mutant dogs)
注意事項
The manufacturer warns against use in unapproved species due to potential severe adverse reactions (including fatalities in dogs). Extreme caution or avoidance is recommended in herding breeds susceptible to the MDR1 (ABCB1) mutation (e.g., Collies, Australian Shepherds, Shelties, Long-haired Whippets) due to a significantly higher risk for severe neurotoxicity.
監測
- Clinical efficacy (resolution of parasites/lesions)
- Signs of neurotoxicity in off-label species (dogs/cats)
藥物動力學
吸收
Bioavailability is, for practical purposes, equal with SC and IM injections in cattle. After SC injection, time to peak plasma concentration in cattle is about 5 days.
分佈
Does not readily cross the blood-brain barrier where mammalian GABA receptors occur.
過量
In field trials, no toxic signs were seen in cattle given up to 25X the recommended dose. In breeding animals (bulls, and cows in early and late pregnancy), a dose 3 times the recommended dose had no effect on breeding performance.
可用產品
劑型
- Injectable solution
- Topical pour-on solution
獸醫用
- Doramectin Injectable Solution: 10 mg/mL in 100 mL, 250 mL, and 500 mL multi-dose vials (Dectomax)
- Doramectin Pour-On Solution: 5 mg/mL in 250 mL, 1 L, 2.5 L and 5 L multidose containers (Dectomax Pour-On)
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 injectable solution should be stored below 86°F (30°C). The topical pour-on solution should be stored below 30°C (86°F) and protected from light.
飼主須知
- 給藥指示：請嚴格遵循獸醫師的劑量指示。若為犬貓的標示外使用，請確保您了解獸醫師說明的相關風險。
- 毒性警告：密切觀察犬貓是否有中毒跡象，如瞳孔放大、極度嗜睡、步態不穩、失明或昏迷。若出現這些症狀，請立即聯繫獸醫師。
- 停藥期規定 (經濟動物)：
- 牛隻：治療後 35-45 天內不得屠宰供人類食用（請確認特定產品標籤）。
- 豬隻：治療後 24 天內不得屠宰。
- 限制：不得用於 20 個月齡（含）以上的泌乳母牛，或將加工為小牛肉的犢牛。尚未建立反芻前犢牛的停藥期。
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