美索巴莫
Methocarbamol
Guaiphenesin carbamate
別名: Robaxin-V · Robaxin-750 · Guaiphenesin carbamate · Labycarbol · Laxan · Lumirelax · Miowas · Musxan · Myocin · Myomethol · Ortoton · Remisol · Rexivin · Robinax · Traumacut · Methocarbamolum
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 |
|---|---|---|---|---|---|
| Relief of moderate conditions | 44 mg/kg IV | IV | As directed | — | 🌎 NA |
| Controlling severe effects of strychnine and tetanus | 55-220 mg/kg IV | IV | As directed | — | 🌎 NA |
| General muscle relaxation (Tablets) | Initially, 132 mg/kg/day PO divided q8h-q12h, then 61-132 mg/kg divided q8-12h | PO | q8h-q12h | Discontinue if no response in 5 days | 🌎 NA |
| Muscle relaxation for intervertebral disk disease (IVDD) | 15-20 mg/kg PO three times daily | PO | TID | — | 🌎 NA |
| Muscle relaxation for certain toxicosis (e.g., strychnine, metaldehyde, tetanus) | 150 mg/kg IV | IV | As directed | — | 🌎 NA |
| Control severe tremors associated with tremorgenic Mycotoxin intoxication | 55-220 mg/kg IV to effect at a rate no more than 2 mL/minute | IV | As directed | — | 🌎 NA |
| Control tremors associated with Guarana (caffeine) toxicity | 50-220 mg/kg IV, administered slowly and to effect; do not exceed 330 mg/kg/day | IV | As directed | — | 🌎 NA |
| General muscle spasms, tetanus, toxicities | 20-45 mg/kg | PO | q8h | As needed | 🌍 EU |
- Relief of moderate conditions: Administer half the estimated dose rapidly, then wait until animal starts to relax and continue administration to effect.
- Controlling severe effects of strychnine and tetanus: Do not exceed 330 mg/kg/day. Administer half the estimated dose rapidly, then wait until animal starts to relax and continue administration to effect.
- General muscle spasms, tetanus, toxicities: Very high doses may be required for tetanus. Recommended not to exceed 330 mg/kg.
貓
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Relief of moderate conditions | 44 mg/kg IV | IV | As directed | — | 🌎 NA |
| Controlling severe effects of strychnine and tetanus | 55-220 mg/kg IV | IV | As directed | — | 🌎 NA |
| General muscle relaxation (Tablets) | Initially, 132 mg/kg/day PO divided q8h-q12h, then 61-132 mg/kg divided q8-12h | PO | q8h-q12h | Discontinue if no response in 5 days | 🌎 NA |
| Adjunctive treatment (control of seizures/muscle tremors) of permethrin toxicity | initially administered at 50-150 mg/kg IV | IV | As directed | — | 🌎 NA |
| General muscle spasms, tetanus, toxicities | 20-45 mg/kg | PO | q8h | As needed | 🌍 EU |
- Relief of moderate conditions: Administer half the estimated dose rapidly, then wait until animal starts to relax and continue administration to effect.
- Controlling severe effects of strychnine and tetanus: Do not exceed 330 mg/kg/day. Administer half the estimated dose rapidly, then wait until animal starts to relax and continue administration to effect.
- Adjunctive treatment (control of seizures/muscle tremors) of permethrin toxicity: First half is given IV slowly over approximately 5-10 minutes and the second half of the dose being given as needed to effect. The dose can be repeated up to a maximum of 330 mg/kg/day; in severely affected cases, the total daily dose can be calculated and given over 24 hours as a constant rate infusion.
- General muscle spasms, tetanus, toxicities: Very high doses may be required for tetanus. Recommended not to exceed 330 mg/kg. Limited literature in cats.
馬
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Moderate conditions | 4.4-22 mg/kg IV to effect | IV | As directed | — | 🌎 NA |
| Severe conditions | 22-55 mg/kg IV | IV | As directed | — | 🌎 NA |
| General muscle relaxation | 15-25 mg/kg IV by slow infusion | IV | As directed | — | 🌎 NA |
| Oral administration | Use 2-3 times the recommended IV dose | PO | As directed | — | 🌎 NA |
| Acute rhabdomyolysis | 15-25 mg/kg slow IV infusion | IV | May repeat up to four times daily if needed | — | 🌎 NA |
- Moderate conditions: ARCI UCGFS Class 4 Drug
牛
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Treatment of CNS hyperactivity | 110 mg/kg IV | IV | As directed | — | 🌎 NA |
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
美索巴莫 (Methocarbamol) 是一種中樞性骨骼肌鬆弛劑，在結構上與癒創木酚甘油醚 (guaifenesin) 相關。在獸醫學中廣泛用於治療骨骼肌的急性發炎和創傷，以及控制嚴重的肌肉痙攣和震顫。
臨床要點：
- 高度有效且經常作為挽救生命的干預措施，用於治療貓的百滅寧 (permethrin) 中毒和狗的震顫性黴菌毒素（例如發霉食物）中毒。
- 提供口服和注射兩種劑型。
- 注射劑型含有聚乙二醇 (PEG) 300，可能會加重原有的腎臟病理變化；因此，對於患有嚴重腎臟疾病的病患，應謹慎使用或避免使用靜脈注射劑型。
- 不會直接放鬆收縮的骨骼肌，而是透過中樞神經系統抑制來發揮作用。
作用機轉
The exact mechanism of action of methocarbamol is not fully understood, but it is known to act centrally rather than peripherally.
- Central CNS Depression: It is believed to cause skeletal muscle relaxation by general central nervous system depression, likely depressing polysynaptic reflexes in the internuncial neurons of the spinal cord.
- No Peripheral Action: It has no direct relaxant effects on striated muscle, nerve fibers, or the motor endplate.
- Secondary Effects: Produces a secondary sedative effect due to its generalized CNS depressant properties.
安全性與警告
禁忌症
- Food-producing animals
- Renal disease (injectable formulation only, due to PEG 300 vehicle)
- Known hypersensitivity to methocarbamol
- Subcutaneous (SC) administration
- No specific contraindications available, but use with caution in renal or hepatic impairment.
不良反應
- Sedation
- Salivation
- Emesis
- Lethargy
- Weakness
- Ataxia
注意事項
Administration Warnings:
- Intravenous Use: Give IV slowly. Do not exceed a rate of 2 mL/minute in dogs and cats. Avoid extravasation as it can cause tissue irritation.
- Do NOT administer subcutaneously (SC).
Organ System Warnings:
- Renal Impairment: The injectable product contains polyethylene glycol (PEG) 300, which can increase pre-existing acidosis and urea retention. Avoid IV use in patients with known or suspected renal pathology.
- Working Animals: May impair the abilities of working animals due to CNS depressant effects.
Reproductive/Nursing:
- FDA Category C for pregnancy. Use with caution as a last resort when benefits clearly outweigh risks. Safety during lactation is unknown, though considered compatible with breastfeeding in humans.
Laboratory Considerations:
- May falsely elevate urinary values of vanillylmandelic acid (VMA) or 5-HIAA.
藥物交互作用
Additive CNS depression may occur when given concurrently.
May cause severe weakness (reported in a human patient with myasthenia gravis).
Additive CNS depression
監測
- Level of muscle relaxation
- Degree of sedation
- Respiratory rate and effort (especially with high IV doses or concurrent CNS depressants)
- Degree of muscle relaxation
- CNS depression/sedation levels
- Renal and hepatic function (if prolonged use)
藥物動力學
半衰期
吸收
In humans, onset of action is about 30 minutes after oral administration. Peak levels occur approximately 2 hours after dosing.
分佈
Limited pharmacokinetic data is available in veterinary species.
代謝
The drug is metabolized to inactive metabolites. Guaifenesin is a minor metabolite of methocarbamol, but due to very low concentrations, it likely has no clinical effect.
排除
Inactive metabolites are excreted primarily into the urine, with small amounts in the feces. In horses, plasma clearances appear to be dose-dependent after IV administration (lower clearances measured after higher doses).
過量
Signs of Toxicity: Overdosage is generally characterized by profound CNS depressant effects, including loss of righting reflex and prostration. Excessive doses in dogs and cats may manifest as emesis, salivation, severe weakness, and ataxia.
Management:
- Decontamination: If the overdose occurred recently via oral administration, emptying the gut (e.g., emesis induction or gastric lavage) may be indicated. Do not induce emesis if the patient's continued consciousness and airway protection are not assured.
- Supportive Care: Treat other clinical signs supportively if severe. Monitor respiratory and cardiovascular function closely.
可用產品
劑型
- Injection
- Oral: 500 mg, 750 mg tablets
獸醫用
- Methocarbamol Tablets: 500 mg (Robaxin-V)
- Methocarbamol Injection: 100 mg/mL in vials of 20 mL and 100 mL (Robaxin-V)
人用標示
- Methocarbamol Tablets: 500 mg & 750 mg (Robaxin, Robaxin-750, generic)
- Methocarbamol Injection: 100 mg/mL in 10 mL vials (Robaxin)
- Robaxin 500 mg tablets
- Robaxin 750 mg tablets
各地核准狀態
POM (Prescription Only Medicine)
POM
暫無法規資料: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
儲存與穩定性
Store tablets at room temperature in tight containers. Store the injection at room temperature and do not freeze. Solutions prepared for IV infusion should not be refrigerated as a precipitate may form. Because a haze or precipitate may form, all diluted intravenous solutions should be physically inspected before administration.
飼主須知
重要提示： 您的寵物在服用此藥物期間，尿液顏色可能會變深（有時呈現黑色、棕色或綠色）。這是一種無害的副作用，無需擔心。
- 嗜睡與行動笨拙： 此藥物通常會引起嗜睡、精神不振和行走不協調（共濟失調）。請將您的寵物安置在安全的受限區域，遠離樓梯、可能跳下的傢俱或其他危險物品，以防受傷。
- 給藥方式： 請嚴格按照處方給藥。如果漏服一劑，請勿在下次給藥時服用雙倍劑量。
- 需報告的副作用： 如果您的寵物出現嚴重嘔吐、過度流口水，或虛弱到無法站立，請立即聯繫您的獸醫師。
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