미다졸람

주사용 벤조디아제핀계 / 진정제 / 항경련제

미다졸람은 수의학에서 마취 전 진정제, 근육 이완제 및 항경련제로 널리 사용되는 속효성 주사용 **벤조디아제핀계 약물**입니다. **임상 요점:** * **독특한 용해도:** 디아제팜과 달리 미다졸람은 바이알(pH < 4)에서는 수용성이지만 생리적 체내 pH(7.4)에서는 지용성으로 변합니다. 이로 인해 침전 없이 다른 수용성 약물(예: 오피오이드 및 케타민)과 안전하게 혼합할 수 있습니다. * **근육 주사 흡수:** 프로필렌 글리콜을 포함하지 않아 근육(IM) 주사 시 통증을 유발하지 않으며 빠르고 안정적으로 흡수되므로 IM 사용 시 디아제팜보다 우수합니다. * **역설적 흥분:** 건강하고 불안해하지 않는 개와 고양이에게 단독으로 투여할 경우, 확실한 진정 효과를 제공하지 못하고 역설적인 불쾌감이나 흥분을 유발할 수 있습니다. 다른 약물(예: 오피오이드, 케타민 또는 알파-2 작용제)과 병용할 때 가장 효과적입니다. * **간질 중첩증:** 진행 중인 발작을 멈추는 데 매우 효과적이며 정맥(IV), 근육(IM) 또는 비강(IN)으로 투여할 수 있습니다.

작용 기전: Midazolam exerts its effects by enhancing the activity of **gamma-aminobutyric acid (GABA)**, the primary inhibitory neurotransmitter in the central nervous system. * **Target:** Binds to specific allosteric benzodiazepine receptors on the **GABA-A receptor** complex. * **Mechanism:** Binding increases the *frequency* of chloride channel openings → influx of chloride ions → hyperpolarization of the postsynaptic neuronal membrane → decreased neuronal excitability. * **Effects:** This depression of subcortical levels (limbic, thalamic, and hypothalamic) produces anxiolytic, sedative, skeletal muscle relaxant, and anticonvulsant effects. Midazolam has approximately twice the affinity for benzodiazepine receptors compared to diazepam, making it more potent with a faster onset and shorter duration of action.

동물 종별 용량

Cats

As a preoperative agent · 0.2-0.4 mg/kg IV or IM with an opioid such as hydromorphone (0.1 mg/kg IV or 0.2 mg/kg IM) · IV/IM · Once
As a preoperative agent · 0.05-0.5 mg/kg; a dose of 0.3 mg/kg being the most effective when mixed with ketamine to allow for intubation. May be used in combination with ketamine in a 50:50 mixture (volume/volume) at a dose of 1 mL/9.1 kg (1 mL/20 lb), this equates to a dose of 0.28 mg/kg of midazolam and 5.5 mg/kg of ketamine. · IV/IM · Once
As a preoperative agent · 0.1-0.5 mg/kg IV · IV · Once
For status epilepticus · 0.07-0.2 mg/kg IV or IM; effects are short-lived, so if seizures recur a CRI can be helpful given at 0.05-0.5 mg/kg/hour. · IV/IM · Once or CRI
Emergency management of seizures including status epilepticus · 0.2-0.3 mg/kg · IV/Intrarectal · Repeat q10min up to 3 times if no clinical effect · As needed for emergency control · Intrarectal route used if venous access is not available.

Horses

As a preoperative agent · 0.011-0.0.44 mg/kg IV · IV · Once
For seizure control in foals · 2-5 mg (total dose) for a 50 kg foal given IV; rapid IV administration may result in apnea and hypotension. A CRI may be used at a dose of 1-3 mg/hour for a 50 kg foal. · IV · Once or CRI
For seizure control in foals · 2-5 mg (total dose) for a 50 kg foal given IV or IM; may be repeated to effect. · IV/IM · To effect

Birds

투여 경로

IVIMIntranasal (IN)PO (syrup or compounded)CRI (Constant Rate Infusion)IntrarectalOromucosal

금기

Hypersensitivity to benzodiazepines
Acute narrow-angle glaucoma
Intra-carotid artery injection (must be avoided)
Neonates (avoid use)

이상반응

Respiratory depression (especially when combined with opioids or other CNS depressants)
Paradoxical excitement, dysphoria, or agitation (especially in cats and dogs when used alone)
Hypotension and bradycardia (when combined with other anesthetics like isoflurane or ketamine)
Pain on injection or local irritation (rare compared to diazepam)
Respiratory depression
Severe hypotension
Paradoxical excitement (occasionally)

약물 상호작용

Inhalational Anesthetics (e.g., Isoflurane) · Midazolam may decrease the dosages required for inhalant anesthetics.
Azole Antifungals (ketoconazole, itraconazole, fluconazole) · May inhibit midazolam metabolism, increasing midazolam blood levels.
Calcium Channel Blockers (diltiazem, verapamil) · May increase midazolam levels.
Cimetidine · May increase midazolam levels by inhibiting hepatic metabolism.
Other CNS Depressants · May increase the risk of profound sedation and respiratory depression.
Macrolide Antibiotics (erythromycin, clarithromycin) · May increase midazolam levels.
Opiates · May increase the hypnotic effects of midazolam; hypotension has been reported when used with meperidine. Combination causes greater respiratory depression.
Phenobarbital · May decrease peak levels and AUC of midazolam via enzyme induction.
Rifampin · May decrease peak levels and AUC of midazolam.
Thiopental · Midazolam may decrease the dosages required for induction.
Propofol · Potentiates effect, reducing the dose required for induction · major
Inhalation anaesthetics · Potentiates effect, reducing the dose required · major

모니터링

Level of sedation and central nervous system depression
Respiratory rate, effort, and oxygenation (especially when combined with other drugs)
Heart rate and blood pressure
Respiratory rate and effort
Blood pressure
Heart rate and rhythm
Level of sedation and consciousness

과용량

Accidental overdoses should be managed with **supportive care** (e.g., cardiovascular and respiratory support), similar to diazepam. * **Reversal Agent:** **Flumazenil** is a specific benzodiazepine antagonist and can be used to reverse midazolam's effects. * However, because midazolam has a very short duration of effect and flumazenil is costly, supportive therapy is usually sufficient for all but the most massive overdoses.

VetSheet 약물 레퍼런스는 면허 수의 전문가를 위한 임상 의사결정 보조 도구이며, 전문적 판단이나 제조사의 최신 라벨을 대신하지 않습니다.