Hidralazina
Hydralazine
Hydralazine HCl
También conocido como: Alphapress · Bionobal · Cesoline · Hydrapres · Hyperex · Hyperphen · Ipolina · Nepresol · Novo-Hylazin · Nu-Hydral · Rolazine · Slow-Apresoline · Supres · apressinum · hydralazini · hydrallazine · Hydralazine hydrochloride · Hidralazina
Revisado por el equipo veterinario de VetSheetActualizado 5 abr 2026Referencia veterinaria basada en la evidencia
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Dosis por especie
🌎 NA — North America🌍 EU — Europe
Perros
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Adjunctive therapy in treatment of heart failure (not receiving ACE inhibitors) | 1 mg/kg (starting dose, titrate up to 3 mg/kg if needed) | PO | q12h | — | 🌎 NA |
| Acute, fulminant heart failure due to severe mitral regurgitation (not receiving ACE inhibitors) | 2 mg/kg | PO | Once | — | 🌎 NA |
| Adjunctive therapy in treatment of heart failure (receiving ACE inhibitors) | 0.5 mg/kg (starting dose, increase in 0.5 mg/kg increments to max 3 mg/kg) | PO | q12h | — | 🌎 NA |
| Short-term treatment of CHF secondary to valve disease | Initial dose of 1 mg/kg PO (additional 0.5-1 mg/kg can be administered to max cumulative 3 mg/kg) | PO | q12h | Short-term | 🌎 NA |
| Treatment of systemic hypertension (Fifth step drug) | 0.5 mg/kg | PO | twice daily | — | 🌎 NA |
| Congestive heart failure / Systemic hypertension | 0.5-3 mg/kg | PO | q8-12h | Long-term | 🌍 EU |
- Adjunctive therapy in treatment of heart failure (not receiving ACE inhibitors): Effective dose is 0.5-3 mg/kg PO q12h. Titrate upwards carefully. If BP monitored, can titrate more rapidly in 1-2 hour intervals.
- Acute, fulminant heart failure due to severe mitral regurgitation (not receiving ACE inhibitors): Given along with IV furosemide. May cause hypotension, but benefits outweigh risks.
- Adjunctive therapy in treatment of heart failure (receiving ACE inhibitors): Give with extreme caution as severe hypotension may occur. Blood pressure monitoring required.
- Short-term treatment of CHF secondary to valve disease: Goal MAP is 60-80 mmHg. Once desired BP achieved, administer PO q12h.
- Treatment of systemic hypertension (Fifth step drug): Added if systolic BP > 160 mmHg after enalapril/benazepril, amlodipine (low then high dose), and spironolactone.
- Congestive heart failure / Systemic hypertension: Start at low dose (0.5-1 mg/kg q12h), monitor blood pressure regularly and increase to 2 mg/kg or even 3 mg/kg q12h if necessary.
Gatos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Adjunctive therapy in treatment of heart failure | start titration at 2.5 mg (total dose) and if necessary, increase up to 10 mg | PO | q12h | — | 🌎 NA |
| Treatment of systemic hypertension (Fourth step drug) | 0.5 mg/kg | PO | twice daily | — | 🌎 NA |
| Systemic hypertension | 2.5-10 mg/cat | PO | q12h | Long-term | 🌍 EU |
- Adjunctive therapy in treatment of heart failure: Follow similar titration protocols as dogs.
- Treatment of systemic hypertension (Fourth step drug): Added if systolic BP > 160 mmHg after amlodipine, ACE inhibitor, and spironolactone.
- Systemic hypertension: Start at low dose and titrate upwards cautiously. Monitor blood pressure regularly.
Caballos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Adjunctive therapy in treatment of heart failure (afterload reducer) | 0.5 mg/kg | IV | Once | — | 🌎 NA |
| Adjunctive therapy in treatment of heart failure (long-term therapy) | 0.5-1.5 mg/kg | PO | q12h | Long-term | 🌎 NA |
- Adjunctive therapy in treatment of heart failure (afterload reducer): ARCI UCGFS Class 3 Drug.
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Resumen
La hidralazina es un potente vasodilatador arteriolar de acción directa utilizado principalmente para el manejo de la hipertensión sistémica y como reductor de la poscarga en el tratamiento adyuvante de la insuficiencia cardíaca congestiva (ICC) en animales pequeños.
- Utilidad clínica: Particularmente beneficiosa en casos de insuficiencia de la válvula mitral, grandes defectos septales o regurgitación aórtica grave, donde reducir la resistencia contra la cual bombea el corazón (poscarga) es crítico.
- ICC refractaria: Se utiliza a menudo cuando los inhibidores de la ECA (como el enalapril) son insuficientes para lograr una mejoría clínica en perros con insuficiencia mitral.
- Terapia combinada: Se combina frecuentemente con diuréticos para contrarrestar su tendencia a causar retención de sodio y agua, y a veces con betabloqueantes para atenuar la taquicardia refleja.
- Limitaciones: No es particularmente útil en el tratamiento de la insuficiencia cardíaca cuando la enfermedad miocárdica primaria (p. ej., miocardiopatía dilatada) es el único problema sin una regurgitación valvular significativa.
Mecanismo de acción
Hydralazine acts as a semicarbazide-sensitive amine oxidase (SSAO) inhibitor, directly relaxing vascular smooth muscle.
- Mechanism: Alters cellular calcium metabolism in smooth muscle → interferes with calcium movements → prevents the initiation and maintenance of the contractile state.
- Vascular Selectivity: Exerts a much greater effect on arterioles than on veins. This selective arterial dilation significantly decreases systemic vascular resistance (SVR) and blood pressure.
- Cardiac Effects: In CHF patients, the reduction in afterload → significantly increases forward cardiac output.
- Compensatory Responses: In non-CHF hypertensive patients, the sudden drop in blood pressure can trigger baroreceptor-mediated reflex tachycardia and activation of the renin-angiotensin-aldosterone system (RAAS) → leading to sodium and water retention.
Seguridad y advertencias
Contraindicaciones
- Known hypersensitivity to hydralazine
- Coronary artery disease
- Hypovolemia
- Preexisting hypotension
- Hypovolaemia
- Renal impairment
- Cerebral bleeding
Efectos adversos
- Weakness and lethargy
- Syncope (fainting)
- Reflex tachycardia
- Sodium and water retention
- GI distress (vomiting, diarrhea)
- Increased creatinine levels
- SLE-like syndrome (documented in humans, theoretical in animals)
- Lacrimation and conjunctivitis
- Peripheral neuritis
- Blood dyscrasias
- Urinary retention
- Constipation
- Severe hypotension
- Anorexia (especially in cats)
- Vomiting (especially in cats)
Precauciones
Dose Titration: Doses must be titrated upwards carefully to avoid severe, life-threatening hypotension.
- Renal Disease: Use with caution. Reduced renal blood flow can activate the RAAS and exacerbate renal injury; pretreatment with an ACE inhibitor and spironolactone is often advised.
- Intracerebral Bleeding: Use with caution due to potential effects on cerebral blood flow.
- Autoimmune Disease: Use cautiously in patients with preexisting autoimmune diseases, as an SLE-like syndrome has been documented in humans.
- Pregnancy: FDA Category C (humans); Papich Class B (veterinary). Safe for use if used cautiously, but crosses the placenta. Excreted in milk but generally considered compatible with nursing.
Interacciones farmacológicas
May cause additive hypotensive effect; usually used for therapeutic advantage
May cause additive hypotensive effect; usually used for therapeutic advantage
Potentially could cause profound hypotension
May cause additive hypotensive effect; usually used for therapeutic advantage
Hydralazine may increase furosemide's renal effects
May cause additive hypotensive effect
Hydralazine may cause decreased pressor effect and may cause additive tachycardia
Enhanced hypotensive effects
Enhanced hypotensive effects
Enhanced hypotensive effects
Enhanced hypotensive effects
Enhanced hypotensive effects
Enhanced hypotensive effects
May cause tachycardia
Reduced pressor response to adrenaline
Monitorización
- Baseline thoracic radiographs
- Mucous membrane color and capillary refill time
- Serum electrolytes and creatinine
- Arterial blood pressure (Target MAP 60-80 mmHg for short-term CHF treatment)
- Venous PO2
- Occasional CBC (due to possibility of blood dyscrasias)
- Systemic blood pressure (frequent monitoring during initiation)
- Heart rate and rhythm
- Renal function (BUN, Creatinine)
- Hydration status and body weight (to monitor for fluid retention)
Farmacocinética
Vida media
Absorción
Rapidly absorbed after oral administration. Onset of action within 1 hour, peak effects at 3-5 hours. High first-pass effect. Food decreases oral bioavailability in dogs by about 63% (though some reports suggest food may enhance tablet bioavailability).
Distribución
Widely distributed in body tissues. Approximately 85% bound to plasma proteins in humans. Crosses the placenta and very small amounts are excreted into milk.
Metabolismo
Extensively metabolized in the liver. N-acetylation is a primary enzymatic pathway, which is mostly absent in dogs, leading to increased risks for toxicity.
Eliminación
Approximately 15% is excreted unchanged in the urine. Duration of action in dogs after oral administration is reportedly 11-13 hours.
Sobredosis
Clinical Signs: Overdoses are characterized by severe hypotension, reflex tachycardia or other arrhythmias, skin flushing, and myocardial ischemia.
Treatment:
- Decontamination: Evacuate gastric contents and administer activated charcoal using standard precautions if ingestion was recent and cardiovascular status is stable.
- Cardiovascular Support: Treat shock using volume expanders. Avoid pressor agents if possible.
- Pressor Agents: If required to maintain blood pressure, use a minimally arrhythmogenic agent (e.g., phenylephrine or methoxamine).
- Additional Support: Digitalis agents may be required. Diligently monitor blood pressure and renal function.
Productos disponibles
Formulaciones
- Oral tablets
- Injection
- 25 mg oral tablet
- 50 mg oral tablet
Etiquetado para humanos
- Hydralazine HCl Oral Tablets: 10 mg, 25 mg, 50 mg & 100 mg (Apresoline, generic)
- Hydralazine Injection: 20 mg/mL in 1 mL vials (generic)
- Apresoline 25 mg tablets
- Apresoline 50 mg tablets
Estado regulador
POM (Prescription Only Medicine). Used under the cascade.
POM (Prescription Only Medicine). Used under the prescribing cascade.
Sin datos reguladores para: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Almacenamiento y estabilidad
Store tablets in tight, light-resistant containers at room temperature. Store injectable product at room temperature; avoid refrigeration or freezing. When mixed with infusion solutions, a color change may occur over 8-12 hours, which does not necessarily indicate a loss in potency.
Información para el cliente
La hidralazina es un medicamento utilizado para reducir la presión arterial y disminuir la carga de trabajo del corazón de su mascota, particularmente si tiene válvulas cardíacas con fugas.
- Cumplimiento estricto: Es crucial administrar este medicamento exactamente como lo recetó su veterinario para maximizar sus beneficios y evitar caídas peligrosas en la presión arterial.
- Qué observar: Contacte a su veterinario de inmediato si su mascota se muestra inusualmente letárgica, débil, deprimida o si se desmaya. Estos pueden ser signos de que su presión arterial ha bajado demasiado (hipotensión).
- Efectos secundarios: Puede notar vómitos o diarrea leves. Si estos persisten, informe a su veterinario.
- Dieta: Pregunte a su veterinario si debe administrar este medicamento con o sin comida, ya que los alimentos pueden afectar la cantidad de fármaco que se absorbe en el sistema de su mascota.
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.