๋ฉ๋ฐํ ๋ฏธ๋
**๋ฉ๋ฐํ ๋ฏธ๋(Medetomidine)**์ ๊ฐ๋ ฅํ ํฉ์ฑ **์ํ-2 ์๋๋ ๋ ๋ฆฐ ์์ฉ์ฒด ์์ฉ์ **๋ก, ์์ํ์์ ๊น์ ์ง์ , ์งํต ๋ฐ ๊ทผ์ก ์ด์ ํน์ฑ์ผ๋ก ๋๋ฆฌ ์ฌ์ฉ๋ฉ๋๋ค. ์ฃผ์ ์์์ ํน์ง์ ๋ค์๊ณผ ๊ฐ์ต๋๋ค: - **์ด์์ฑ(Biphasic) ์ฌํ๊ด ๋ฐ์**: ์ด๊ธฐ์ ๋ง์ด ํ๊ด ์์ถ์ด ์ผ์์ ์ธ ๊ณ ํ์์ ์ ๋ฐํ๋ฉฐ, ์ดํ ๋ฐ์ฌ์ฑ ์๋งฅ๊ณผ ์ ์ ํ์ ๋๋ ๊ฒฝ๋ฏธํ ์ ํ์์ด ๋ค๋ฐ๋ฆ ๋๋ค. - **๊ฐ์ญ์ฑ**: **์ํฐํ๋ฉ์กธ(Atipamezole)**๊ณผ ๊ฐ์ ํน์ด์ ์ํ-2 ๊ธธํญ์ ๋ฅผ ์ฌ์ฉํ์ฌ ๊ทธ ํจ๊ณผ๋ฅผ ๋น ๋ฅด๊ณ ์์ ํ๊ฒ ์ญ์ ์ํฌ ์ ์์ต๋๋ค. - **์ ์ฒดํํ**: ๋ฉ๋ฐํ ๋ฏธ๋์ ๋ ๊ฐ์ง ์ ์ฒด ์ด์ฑ์ง์ฒด์ ๋ผ์ธ๋ฏธ ํผํฉ๋ฌผ์ ๋๋ค. ํ์ฑ ๊ฑฐ์ธ์ ์ด์ฑ์ง์ฒด๋ **๋ฑ์ค๋ฉ๋ฐํ ๋ฏธ๋(Dexmedetomidine)**์ด๋ฉฐ, ํ๋ ์์ํ ์์ฅ์์ ๋ผ์ธ๋ฏธ ๋ฉ๋ฐํ ๋ฏธ๋์ ๋์ฒดํ๊ณ ์์ต๋๋ค. - **์๋์ง ํจ๊ณผ**: ์คํผ์ค์ด๋, ์ผํ๋ฏผ ๋ฐ ๊ธฐํ ๋ง์ทจ์ ์ ๋์ ์๋์ง ํจ๊ณผ๋ฅผ ๋ํ๋ด์ด ๋ณ์ฉ ๋ง์ทจ์ ์ ์๊ตฌ ์ฉ๋์ ํฌ๊ฒ ์ค์ผ ์ ์์ต๋๋ค. > **์์ ํ**: ์ฒด์ฑ ๋ฐ ๋ด์ฅ ์งํต ํจ๊ณผ๊ฐ ๋ฐ์ด๋์ง๋ง, ์ง์ ํจ๊ณผ๊ฐ ์งํต ํจ๊ณผ๋ณด๋ค ์ค๋ ์ง์๋๋ ๊ฒฝํฅ์ด ์์ต๋๋ค. ํ์๊ฐ ๊น๊ฒ ์ง์ ๋ ๊ฒ์ฒ๋ผ ๋ณด์ด๋๋ผ๋ ํฐ ์๋ฆฌ๋ ๊ฑฐ์น ์ทจ๊ธ์ ์ํด ๊ฐ์๊ธฐ ๊นฐ ์ ์์ต๋๋ค.
์์ฉ ๊ธฐ์ : Medetomidine produces its effects by binding to and activating **pre- and postsynaptic alpha-2 adrenergic receptors** in the central and peripheral nervous systems. - **Central Nervous System**: Activation of alpha-2 receptors in the **locus coeruleus** โ inhibition of adenylyl cyclase โ decreased cAMP โ efflux of potassium (hyperpolarization) โ decreased release of **norepinephrine**. This suppression of sympathetic outflow results in profound sedation, anxiolysis, and analgesia. - **Cardiovascular System**: Activation of peripheral **alpha-1 and alpha-2b receptors** in vascular smooth muscle โ profound vasoconstriction โ increased systemic vascular resistance (hypertension) โ baroreceptor-mediated increased vagal tone โ **reflex bradycardia**. - **Endocrine/Metabolic**: Inhibits insulin release from pancreatic beta cells โ transient **hyperglycemia**. Decreases antidiuretic hormone (ADH) release โ increased diuresis. Medetomidine is highly selective, with an alpha-2:alpha-1 selectivity ratio of 1620:1 (approximately 10 times more specific than xylazine).
๋๋ฌผ ์ข ๋ณ ์ฉ๋
- Sedation/analgesia ยท 40-80 micrograms/kg IM ยท IM ยท Single dose ยท Higher doses increase duration, not depth of sedation
- For use with an IM opioid ยท 5-10 micrograms/kg ยท IM ยท Single dose
- Sedation/analgesia ยท 0.001-0.01 mg/kg (1-10 micrograms/kg) IV, IM or SC ยท IV/IM/SC ยท Single dose
- Large, exotic cat (tigers, etc.) immobilization ยท Midazolam (0.1 mg/kg) plus medetomidine (0.05-0.07 mg/kg) IM followed by ketamine (4-10 mg/kg) IM, if needed. May antagonize with atipamezole (0.25-0.35 mg/kg) IV, SC. ยท IM ยท Single dose
- Premedication (in combination with an opioid) ยท 5-20 ฮผg (micrograms)/kg ยท IV/IM/SC ยท single dose ยท Analgesia lasts approx 1 hour at 10 ฮผg/kg ยท Use lower end of dose range for IV administration.
- Management of excitation in the recovery period ยท 1-2 ฮผg/kg ยท IV ยท single dose ยท Animals must be monitored carefully following administration.
- Perioperative analgesia and rousable sedation ยท 2-4 ฮผg/kg/h ยท IV ยท CRI ยท perioperative period ยท Particularly useful when administered as an adjunct to opioid-mediated analgesia.
- Sedative/analgesic ยท 15 minutes prior to medetomidine, give atropine (0.05 mg/kg) or glycopyrrolate (0.01 mg/kg) then give medetomidine at 60-80 micrograms/kg IM or SC. ยท IM/SC ยท Single dose ยท Sedation lasts for up to 3 hours ยท May be reversed with atipamezole (400 micro-grams/kg IM)
ํฌ์ฌ ๊ฒฝ๋ก
๊ธ๊ธฐ
- Cardiac disease
- Respiratory disorders
- Liver or kidney diseases
- Shock or severe debilitation
- Animals stressed due to heat, cold, or fatigue
- Pregnancy (insufficient safety data; use only if benefits clearly outweigh risks)
- Cardiovascular disease
- Systemic disease
- Geriatric patients
- Pregnant animals
- Conditions where vomiting is contraindicated (e.g., gastrointestinal foreign body, raised intraocular pressure)
- Diabetes mellitus
์ด์๋ฐ์
- Bradycardia (often profound)
- Atrioventricular (AV) blocks
- Decreased respiratory rate and potential apnea
- Hypothermia
- Increased urination (diuresis)
- Vomiting (especially in cats)
- Hyperglycemia
- Pain on intramuscular injection
- Blanched or cyanotic mucous membranes (due to peripheral vasoconstriction)
- Rarely: prolonged sedation, paradoxical excitation, hypersensitivity, death from circulatory failure
- Bradycardia
- Decreased cardiac output
- Initial hypertension followed by normotension/hypotension
- Vomiting (especially common after IM administration)
- Diuresis (due to ADH suppression)
์ฝ๋ฌผ ์ํธ์์ฉ
- Atropine / Glycopyrrolate ยท Controversial. Using anticholinergics to treat medetomidine-induced bradycardia can lead to severe hypertension, increased myocardial work, and arrhythmias. Concomitant use is generally discouraged, especially at higher medetomidine doses (>20 mcg/kg).
- Opiates (Fentanyl, Butorphanol, Meperidine) ยท Synergistic enhancement of sedation and analgesia. Adverse cardiovascular and respiratory effects may also be pronounced. Reduced dosages and careful monitoring are advised.
- Propofol ยท When used after medetomidine, severe hypoxemia may occur. Significant dosage reductions of propofol are required along with adequate respiratory monitoring.
- Yohimbine ยท May reverse the effects of medetomidine, but atipamezole is the preferred and more specific reversal agent.
- Other anesthetic agents (e.g., propofol, alfaxalone) ยท Significantly reduces the dose required for induction and maintenance of anesthesia. ยท major
- Volatile anesthetics (e.g., isoflurane, sevoflurane) ยท Reduces the dose required to maintain anesthesia by up to 70%. ยท major
- Sympathomimetic amines ยท Contraindicated; may cause severe cardiovascular complications. ยท major
- Opioids ยท Synergistic sedation and analgesia (beneficial interaction). ยท moderate
๋ชจ๋ํฐ๋ง
- Level of sedation and analgesia
- Heart rate and rhythm (ECG recommended in high-risk patients)
- Body temperature (monitor for hypothermia)
- Blood pressure
- Respiratory rate and depth
- Pulse oximetry (SpO2)
- Heart rate and rhythm (bradycardia is expected, but monitor for severe arrhythmias)
- Blood pressure (initial hypertension followed by normotension/hypotension)
- Oxygen saturation (SpO2)
- Body temperature (risk of hypothermia due to reduced metabolic rate and peripheral vasoconstriction)
- Depth of sedation
๊ณผ์ฉ๋
Single doses of up to **5X (IV)** and **10X (IM)** have been tolerated in dogs, though severe adverse effects (profound bradycardia, AV blocks, respiratory depression) can occur. Death has occurred rarely in dogs (1 in 40,000) receiving 2X doses. > **Important**: Treatment of medetomidine-induced bradycardia with anticholinergic agents (atropine or glycopyrrolate) is **not recommended** due to the risk of severe hypertension, increased myocardial oxygen demand, and arrhythmias. **Atipamezole** (an alpha-2 antagonist) is the safest and most effective choice to reverse medetomidine-induced cardiovascular and sedative effects.
VetSheet ์ฝ๋ฌผ ๋ ํผ๋ฐ์ค๋ ๋ฉดํ ์์ ์ ๋ฌธ๊ฐ๋ฅผ ์ํ ์์ ์์ฌ๊ฒฐ์ ๋ณด์กฐ ๋๊ตฌ์ด๋ฉฐ, ์ ๋ฌธ์ ํ๋จ์ด๋ ์ ์กฐ์ฌ์ ์ต์ ๋ผ๋ฒจ์ ๋์ ํ์ง ์์ต๋๋ค.