右美托咪啶
Dexmedetomidine
Dexmedetomidine Hydrochloride
別名: Dexdomitor · Precedex · (S)-medetomidine · MPV 1440 · MPV 295 · MPV 785
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
經審核的 v13 劑量證據
經審核的非計算證據經審核的非計算證據 (2)
只供證據參考，不會自動計算
Light sedation (often used for preanesthesia)
a) Light sedation (often used for preanesthesia): 5 – 15 µg/kg IV, IM, or SC
必須同時考慮的臨床上下文 (7)
- 1. Dexmedetomidine dosages depend on the combination of drugs used and the dosage(s) of the other drug(s). Premedication with dexmedetomidine will significantly reduce the dose of the induction agent required and will reduce volatile anesthetic requirements for maintenance anesthesia. All anesthetic agents used for induction or maintenance of anesthesia should be administered to effect.
- 2. Dose adjustments will also need to be made to account for the degree of desired sedation; type, duration, and pain level of the procedure; and patient temperament and body weight/size.
- 3. Dosing based on body surface area (BSA; or allometric scaling) is not common in clinical practice but decreases the variability in drug response between giant/large and small/toy breed dogs. See Conversion Tables: Body Weight (kg) to Body Surface Area (m 2 ).
- 4. For all dosages, the low end of the dose range is generally appropriate for IV administration, whereas the mid-upper range is most appropriate for IM or SC administration. Higher dosages will provide more profound sedation and analgesia.
- 5. When SC administration is used, the speed of sedation is slower, and the level of sedation is lighter and inconsistent. For more predictable sedation, IM or IV administration is recommended.
- 6. The effects of dexmedetomidine can be reversed with atipamezole. It is most often dosed by volume at ½ or the same volume of dexmedetomidine that was administered and given IM. See Atipamezole.
- Store the injection at room temperature (ie, 15°C-30°C [59°F-86°F]); do not freeze. Discard unused product 90 days after first piercing the vial.
只供證據參考，不會自動計算
Deep sedation
c) Deep sedation: 40 µg/kg IV, IM, or SC
必須同時考慮的臨床上下文 (7)
- 1. Dexmedetomidine dosages depend on the combination of drugs used and the dosage(s) of the other drug(s). Premedication with dexmedetomidine will significantly reduce the dose of the induction agent required and will reduce volatile anesthetic requirements for maintenance anesthesia. All anesthetic agents used for induction or maintenance of anesthesia should be administered to effect.
- 2. Dose adjustments will also need to be made to account for the degree of desired sedation; type, duration, and pain level of the procedure; and patient temperament and body weight/size.
- 3. Dosing based on body surface area (BSA; or allometric scaling) is not common in clinical practice but decreases the variability in drug response between giant/large and small/toy breed dogs. See Conversion Tables: Body Weight (kg) to Body Surface Area (m 2 ).
- 4. For all dosages, the low end of the dose range is generally appropriate for IV administration, whereas the mid-upper range is most appropriate for IM or SC administration. Higher dosages will provide more profound sedation and analgesia.
- 5. When SC administration is used, the speed of sedation is slower, and the level of sedation is lighter and inconsistent. For more predictable sedation, IM or IV administration is recommended.
- 6. The effects of dexmedetomidine can be reversed with atipamezole. It is most often dosed by volume at ½ or the same volume of dexmedetomidine that was administered and given IM. See Atipamezole.
- Store the injection at room temperature (ie, 15°C-30°C [59°F-86°F]); do not freeze. Discard unused product 90 days after first piercing the vial.
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
右美托咪啶是一種強效且高度特異性的Alpha-2 腎上腺素受體激動劑，在獸醫學中主要用作鎮靜劑、鎮痛劑和麻醉前導藥。它是美托咪啶的右旋對映異構體，效力約為消旋混合物的兩倍。
作用機制
Dexmedetomidine acts as a highly selective agonist at pre-synaptic alpha-2 adrenergic receptors in the central and peripheral nervous systems.
- CNS Effects: Activation of alpha-2 receptors in the locus coeruleus → decreased norepinephrine release → profound sedation, anxiolysis, and analgesia.
- Cardiovascular Effects: Activation of peripheral post-synaptic alpha-2B receptors in vascular smooth muscle → intense vasoconstriction → increased systemic vascular resistance (SVR) → reflex bradycardia mediated by baroreceptors. Central alpha-2A activation subsequently decreases sympathetic outflow.
- Other Effects: Decreases GI secretions, alters intestinal motility, induces diuresis (via inhibition of ADH), and causes mild muscle relaxation.
安全性與警告
禁忌症
- Cardiovascular disease
- Respiratory disorders
- Liver or kidney diseases
- Shock or severe debilitation
- Stress due to extreme heat, cold, or fatigue
- Puppies < 16 weeks (US label) or < 6 months (UK label)
- Kittens < 12 weeks (US label) or < 5 months (UK label)
- Hypersensitivity to the active substance
不良反應
- Bradycardia (profound)
- Occasional AV blocks
- Decreased respiration / Apnea
- Hypothermia
- Urination
- Vomiting
- Hyperglycemia
- Pain on injection (IM)
- Prolonged sedation
- Paradoxical excitation
- Hypersensitivity
- Pulmonary edema
- Death from circulatory failure (rare)
- Muscle tremors
- Transient hypertension
- Reduced tear production
注意事項
Cardiovascular Warning: Due to pronounced cardiovascular effects (bradycardia, vasoconstriction), only clinically healthy dogs and cats should be treated.
- Seizure Disorders: Use with caution in animals with or prone to developing seizures; may lower the seizure threshold.
- Ocular Care: Blinking may be impaired and tear production reduced; eye lubricants should be applied during sedation.
- Pregnancy/Nursing: Not recommended for use in pregnant or breeding animals unless benefits clearly outweigh risks (FDA Category C). Safe use during nursing is not established.
藥物相互作用
Effects may be additive; dosage reduction of one or both agents may be required. General anesthetic requirements may be reduced between 30-60%.
Can significantly increase arterial blood pressure and heart rate; use together is not recommended in dogs due to increased cardiac workload.
Possesses alpha agonist effects; do not use to treat cardiac effects caused by dexmedetomidine.
May reverse the effects, but atipamezole is preferred for clinical use.
監測
- Level of sedation and analgesia
- Heart rate and rhythm
- Blood pressure
- Respiration rate and pulse oximetry
- Body temperature (monitor for hypothermia)
藥物動力學
半衰期
吸收
Dogs: IM bioavailability 60%, peak plasma levels in ~35 minutes. Cats: IM peak plasma levels in ~15 minutes. OTM (buccal) administration provides similar clinical effects to IM.
分佈
Dogs: Vd is 0.9 L/kg. Cats: Vd is 2.2 L/kg.
代謝
Primarily metabolized in the liver via glucuronidation and N-methylation. No active metabolites.
排除
Eliminated primarily in the urine and to a lesser extent in the feces.
過量
Single doses of up to 5X (IV) and 10X (IM) were tolerated in dogs, but adverse effects (heart block, PVCs, tachycardia, profound sedation) can occur.
Important: Treatment of dexmedetomidine-induced bradycardia with anticholinergic agents (atropine or glycopyrrolate) is usually not recommended due to the risk of severe hypertension and arrhythmias.
Atipamezole is the safest and most effective choice to reverse any dexmedetomidine-induced effects or overdose.
可用產品
劑型
- Injection: 0.5 mg/mL (500 mcg/mL)
- Concentrated Solution for Injection: 100 mcg/mL
獸醫用
- Dexmedetomidine HCl 0.5 mg/mL (500 micrograms/mL) in 10 mL multidose vials (Dexdomitor)
人用標示
- Dexmedetomidine HCl Concentrated Solution for Injection: 100 micrograms/mL in 2 mL vials (Precedex)
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
Store the injection at room temperature (15-30°C); do not freeze. Can be mixed in the same syringe with butorphanol, ketamine, buprenorphine, hydromorphone, or morphine with no pharmacological risk.
飼主須知
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