メデトミジン

使用用途

• Sedation/analgesia
• For use with an IM opioid
• Sedation/analgesia
• Large, exotic cat (tigers, etc.) immobilization
• Premedication (in combination with an opioid)
• Management of excitation in the recovery period
• Perioperative analgesia and rousable sedation
• Sedative/analgesic
• Injectable anesthesia
• Sedation/analgesia
• Chemical restraint (Rats)
• Chemical restraint (Guinea pig)
• Chemical restraint (Rabbits)

投与方法

考えられる副作用

• 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

注意事項と禁忌

• 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
• - **Agitated Patients**: Dogs that are extremely agitated or excited may have a decreased response due to high circulating catecholamines overriding the receptor. Allow dogs to rest quietly before administration. Do not re-dose if they fail to respond. - **Age Extremes**: Use with extreme caution in very young or geriatric animals due to reduced cardiovascular reserve. - **Hematologic**: Medetomidine can inhibit ADP-induced platelet aggregation. - **Reversal**: Treat medetomidine-induced bradycardia or excessive sedation with **atipamezole** rather than anticholinergics.

薬物相互作用

• Atropine / Glycopyrrolate: 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): Synergistic enhancement of sedation and analgesia. Adverse cardiovascular and respiratory effects may also be pronounced. Reduced dosages and careful monitoring are advised.
• Propofol: When used after medetomidine, severe hypoxemia may occur. Significant dosage reductions of propofol are required along with adequate respiratory monitoring.
• Yohimbine: May reverse the effects of medetomidine, but atipamezole is the preferred and more specific reversal agent.
• Other anesthetic agents (e.g., propofol, alfaxalone): Significantly reduces the dose required for induction and maintenance of anesthesia.
• Volatile anesthetics (e.g., isoflurane, sevoflurane): Reduces the dose required to maintain anesthesia by up to 70%.
• Sympathomimetic amines: Contraindicated; may cause severe cardiovascular complications.
• Opioids: Synergistic sedation and analgesia (beneficial interaction).

よくある質問