Midazolam
Midazolam hydrochloride
También conocido como: Versed · Dormicum · Dormonid · Fulsed · Hypnovel · Midaselect · Zolamid · Buccolam · Epistatus · Midazolam HCl · Ro-21-3981/003 · Midazolamum · Midazolam hydrochloride
Revisado por el equipo veterinario de VetSheetActualizado 5 abr 2026Referencia veterinaria basada en la evidencia
Evidencia posológica v13 auditada
Evidencia revisada no calculableEvidencia revisada no calculable (1)
Solo evidencia; no apta para cálculo automático
Preanesthetic agent (extra-label)
Preanesthetic agent (extra-label): 0.5 – 5 mg/kg IM or IV
Contexto clínico obligatorio (2)
- NOTE: There are many potential combinations that have been suggested; the following are examples and not inclusive. For additional information, refer to other anesthesia-specific references. 25
- Store midazolam injection at room temperature (15°C-30°C [59°F-86°F]) and protected from light. After being frozen for 3 days and allowed to thaw at room temperature, the injectable product is physically stable. Midazolam is stable at a pH range of 3 to 3.6.
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Resumen
El midazolam es una benzodiacepina parenteral de acción corta ampliamente utilizada en medicina veterinaria como sedante preanestésico, relajante muscular y anticonvulsivo.
Perlas clínicas:
- Solubilidad única: A diferencia del diazepam, el midazolam es hidrosoluble en el vial (a un pH < 4) pero se vuelve altamente liposoluble al pH fisiológico corporal (7.4). Esto permite mezclarlo de forma segura con otros fármacos hidrosolubles (como opioides y ketamina) sin que se precipiten.
- Absorción IM: Debido a que no contiene propilenglicol, el midazolam no causa ardor al administrarse por vía intramuscular (IM) y se absorbe de manera rápida y fiable por esta vía, lo que lo hace superior al diazepam para uso IM.
- Excitación paradójica: Cuando se administra solo a perros y gatos sanos y sin ansiedad, el midazolam a menudo no logra proporcionar una sedación fiable y puede causar disforia o excitación paradójica. Es más eficaz cuando se combina con otros agentes (p. ej., opioides, ketamina o agonistas alfa-2).
- Estado epiléptico: Es altamente eficaz para detener convulsiones activas y puede administrarse por vía IV, IM o intranasal (IN).
Mecanismo de acción
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.
Seguridad y advertencias
Contraindicaciones
- Hypersensitivity to benzodiazepines
- Acute narrow-angle glaucoma
- Intra-carotid artery injection (must be avoided)
- Neonates (avoid use)
Efectos adversos
- 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)
- Severe hypotension
- Paradoxical excitement (occasionally)
Precauciones
High-Risk Patients: Use cautiously in patients with hepatic or renal disease, and in debilitated or geriatric patients.
- Cardiovascular/Respiratory: Administer with extreme caution to patients in coma, shock, or with significant respiratory depression. Patients with congestive heart failure may eliminate the drug more slowly.
- Anesthetic Combinations: While midazolam alone has minimal cardiorespiratory effects, combining it with opioids, ketamine, or inhalants can lead to significant respiratory depression, bradycardia, or hypotension.
- Pregnancy: FDA Category D in humans. May cause congenital abnormalities if used in the first trimester. Excreted in milk and may cause CNS effects in nursing neonates.
Interacciones farmacológicas
Midazolam may decrease the dosages required for inhalant anesthetics.
May inhibit midazolam metabolism, increasing midazolam blood levels.
May increase midazolam levels.
May increase midazolam levels by inhibiting hepatic metabolism.
May increase the risk of profound sedation and respiratory depression.
May increase midazolam levels.
May increase the hypnotic effects of midazolam; hypotension has been reported when used with meperidine. Combination causes greater respiratory depression.
May decrease peak levels and AUC of midazolam via enzyme induction.
May decrease peak levels and AUC of midazolam.
Midazolam may decrease the dosages required for induction.
Potentiates effect, reducing the dose required for induction
Potentiates effect, reducing the dose required
May enhance the sedative effect
May enhance the sedative effect
May enhance the sedative effect
May increase the hypnotic and hypotensive effects of midazolam; enhances sedation
Inhibits the metabolism of midazolam
Monitorización
- 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
- Heart rate and rhythm
- Level of sedation and consciousness
Farmacocinética
Vida media
Absorción
Following IM injection, midazolam is rapidly and nearly completely (91%) absorbed. Oral absorption is good, but bioavailability is low (31-72%) due to a rapid first-pass effect. Rectal bioavailability in dogs is very low. Intranasal administration (especially via compounded gel) provides good absorption and high peak levels.
Distribución
Highly protein bound (94-97%). Due to its high lipophilicity at physiologic pH, it rapidly crosses the blood-brain barrier. Changes in plasma protein concentrations can significantly alter the response to a given dose.
Metabolismo
Metabolized in the liver, principally by microsomal oxidation. Forms an active metabolite (alpha-hydroxymidazolam), which has a very short half-life and negligible clinical effects.
Eliminación
Eliminated primarily via hepatic metabolism and subsequent excretion. The duration of activity is considerably shorter than that of diazepam.
Sobredosis
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.
Productos disponibles
Formulaciones
- Injection (solution)
- Oral syrup
- Injectable solution: 1 mg/ml, 2 mg/ml, 5 mg/ml
- Oromucosal solution: 5 mg/ml (in 0.5 ml, 1 ml, 1.5 ml, 2 ml pre-filled syringes)
- Oromucosal solution: 10 mg/ml pre-filled syringe
Veterinario
- None (No veterinary-labeled products currently available)
- Buccolam
- Epistatus
- Hypnovel
Etiquetado para humanos
- Midazolam HCl Injection: 1 mg/mL in 2 mL, 5 mL, 10 mL vials
- Midazolam HCl Injection: 5 mg/mL in 1 mL, 2 mL, 5 mL, 10 mL vials & 2 mL syringes
- Midazolam HCl Syrup: 2 mg/mL in 118 mL
- Buccolam
- Epistatus
- Hypnovel
Estado regulador
POM
POM-V
Sin datos reguladores para: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Almacenamiento y estabilidad
Store midazolam injection at room temperature (15°-30°C) and protect from light. It is physically stable after being frozen for 3 days and thawed. Midazolam is stable at a pH from 3-3.6. Compounded oral suspensions (e.g., with Syrpalta) retain >90% potency for 56 days when stored at 7°C, 20°C, or 40°C and protected from light.
Información para el cliente
Nota: El midazolam se administra casi exclusivamente en un entorno hospitalario veterinario o bajo supervisión profesional directa.
- Propósito: Su mascota puede recibir este medicamento para ayudarle a relajarse antes de una cirugía, para proporcionar relajación muscular o para detener rápidamente una convulsión activa.
- Cambios de comportamiento: Si se administra solo, algunas mascotas (especialmente perros y gatos sanos) pueden volverse temporalmente inquietas, quejumbrosas o descoordinadas en lugar de somnolientas. Esta es una reacción conocida y se resuelve rápidamente.
- Seguridad: Debido a que puede afectar la respiración y la frecuencia cardíaca cuando se combina con otros anestésicos, su equipo veterinario monitoreará de cerca los signos vitales de su mascota mientras esté bajo los efectos del fármaco.
La referencia de medicamentos de VetSheet está destinada a profesionales veterinarios autorizados como ayuda para la toma de decisiones clínicas, no como sustituto del criterio profesional ni del prospecto actual del fabricante.