Hidroclorotiazida
Hydrochlorothiazide
6-chloro-3,4-dihydro-2H-1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide
También conocido como: HydroDIURIL · Microzide · Aldactazide · Hydro-Par · Ezide · Co-amilozide · Moduretic · HCTZ · hidroclorotiazida · hydrochlorothiazidum
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 |
|---|---|---|---|---|---|
| Treatment of nephrogenic diabetes insipidus | 2 mg/kg PO twice daily with a low sodium diet | PO | twice daily | — | 🌎 NA |
| Treatment of nephrogenic diabetes insipidus | 2.5-5 mg/kg PO twice daily | PO | twice daily | — | 🌎 NA |
| Treatment of systemic hypertension | 1 mg/kg PO q12-24h | PO | q12-24h | — | 🌎 NA |
| Prevention of recurrent calcium oxalate uroliths with renal hypercalcuria | 2 mg/kg q12h PO | PO | q12h | — | 🌎 NA |
| Prevention of recurrent calcium oxalate uroliths with renal hypercalcuria | 2.2 mg/kg PO q12h | PO | q12h | — | 🌎 NA |
| Prevention of recurrent calcium oxalate uroliths with renal hypercalcuria | 2-4 mg/kg PO q12h | PO | q12h | — | 🌎 NA |
| Diuretic for heart failure (refractory to furosemide alone) | 2-4 mg/kg PO q12h | PO | q12h | — | 🌎 NA |
| Adjunctive treatment of heart failure | 2 mg/kg PO q12h | PO | q12h | — | 🌎 NA |
| Ascites secondary to right-sided heart failure | 2 mg/kg initially on an every other day bases | PO | every other day | — | 🌎 NA |
| Ascites in patients with liver disease | 0.5-1 mg/kg PO twice daily | PO | twice daily | — | 🌎 NA |
| As a diuretic (general) | 1-4 mg/kg PO q12h | PO | q12h | — | 🌎 NA |
| Refractory congestive heart failure / Calcium oxalate urolithiasis prevention / Hypertension | 0.5-4 mg/kg | PO | q12-24h | Long-term | 🌍 EU |
- Treatment of nephrogenic diabetes insipidus: Based on a case report
- Treatment of systemic hypertension: As a second choice agent; may combine with spironolactone (1-2 mg/kg PO q12 hours) to reduce potassium loss
- Prevention of recurrent calcium oxalate uroliths with renal hypercalcuria: Usually added when dietary therapy does not adequately control calcium oxalate crystalluria
- Prevention of recurrent calcium oxalate uroliths with renal hypercalcuria: Repeat urinalysis q2-4 weeks and monitor serum electrolytes within several weeks of initial dose and within 2 weeks of dosage adjustment
- Diuretic for heart failure (refractory to furosemide alone): In combination with furosemide
- Adjunctive treatment of heart failure: When a dog requires 4-5 mg/kg PO q8h of furosemide and continues to exhibit clinical signs of congestion, reduce the furosemide dose by 50% and add hydrochlorothiazide
- Ascites secondary to right-sided heart failure: In addition to furosemide, spironolactone, ACE inhibitors, dietary sodium restriction; monitor electrolytes and renal function
- Ascites in patients with liver disease: Using the fixed-dose combination with spironolactone (Aldactazide); dosed empirically based on the spironolactone content
- Refractory congestive heart failure / Calcium oxalate urolithiasis prevention / Hypertension: Start at low dose and titrate upwards every 5-10 days, to effect. Monitor urea, creatinine, electrolytes and blood pressure before increasing dose.
Gatos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Treatment of systemic hypertension | 1 mg/kg PO q12-24h | PO | q12-24h | — | 🌎 NA |
| Treatment of systemic hypertension | 2-4 mg/kg PO q12h | PO | q12h | — | 🌎 NA |
| Diuretic for heart failure | 1-2 mg/kg PO q12h | PO | q12h | — | 🌎 NA |
| Ascites in patients with liver disease | 0.5-1 mg/kg PO twice daily | PO | twice daily | — | 🌎 NA |
| To reduce calcium oxalate saturation in urine | 1 mg/kg PO q12h | PO | q12h | — | 🌎 NA |
| Refractory congestive heart failure / Calcium oxalate urolithiasis prevention / Hypertension | 1-2 mg/kg | PO | q12-24h | Long-term | 🌍 EU |
- Treatment of systemic hypertension: As a second choice agent; may combine with spironolactone (1-2 mg/kg PO q12 hours) to reduce potassium loss
- Treatment of systemic hypertension: Not effective as a single agent in cats, and may be contraindicated (e.g., chronic renal failure). Possibly helpful acutely with retinal detachment.
- Diuretic for heart failure: In combination with furosemide in patients who have become refractory to furosemide alone
- Ascites in patients with liver disease: Using the fixed-dose combination with spironolactone (Aldactazide); dosed empirically based on the spironolactone content
- To reduce calcium oxalate saturation in urine: Study done in normal cats, unknown what effect HCTZ will have in cats with spontaneously occurring calcium oxalate urolithiasis
- Refractory congestive heart failure / Calcium oxalate urolithiasis prevention / Hypertension: Start at low dose and titrate upwards cautiously. Monitor urea, creatinine, electrolytes and blood pressure.
Caballos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Adjunctive therapy of hyperkalemic periodic paralysis (HyPP) | 0.5-1 mg/kg PO q12h | PO | q12h | — | 🌎 NA |
- Adjunctive therapy of hyperkalemic periodic paralysis (HyPP): When diet adjustment does not control episodes. Note: ARCI UCGFS Class 4 Drug
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Resumen
La hidroclorotiazida (HCTZ) es un diurético tiazídico de eficacia moderada que ha sido reemplazado en gran medida por los diuréticos de asa (como la furosemida) para el manejo general del edema en medicina veterinaria, pero sigue siendo muy valioso para indicaciones específicas.
Los usos clínicos clave incluyen:
- Urolitiasis por oxalato de calcio: Se utiliza para prevenir la recurrencia en perros (y potencialmente en gatos) debido a su capacidad única para disminuir la excreción urinaria de calcio (efecto hipocalciúrico).
- Hipertensión sistémica: A menudo se utiliza como agente antihipertensivo adyuvante o de segunda línea.
- Diabetes insípida nefrogénica (DI): Reduce paradójicamente el gasto urinario en pacientes con DI y sirve como terapia farmacológica primaria para la forma nefrogénica.
- Insuficiencia cardíaca refractaria: Se utiliza secuencialmente con diuréticos de asa para superar la resistencia a los diuréticos (bloqueo secuencial de la nefrona).
- Parálisis periódica hiperpotasémica (HyPP): Se utiliza en caballos como alternativa a la acetazolamida cuando el manejo dietético es insuficiente.
Perla clínica: Aunque el monográfico destaca la "hipoglucemia" en los puntos destacados para el prescriptor, las tiazidas son conocidas en realidad por causar o exacerbar la hiperglucemia al disminuir la liberación de insulina y la utilización periférica de glucosa. Se utilizan ocasionalmente para controlar la hipoglucemia hiperinsulinémica (p. ej., insulinoma), aunque el diazóxido es más común.
Mecanismo de acción
Hydrochlorothiazide acts primarily on the distal convoluted tubule (DCT) (cortical diluting segment) of the nephron.
- Diuretic Effect: It competitively antagonizes the Na⁺/Cl⁻ cotransporter (NCC) → inhibits sodium and chloride reabsorption → enhances excretion of Na⁺, Cl⁻, and water.
- Electrolyte Alterations: Increased distal delivery of Na⁺ stimulates the renin-angiotensin-aldosterone system (RAAS) → increased aldosterone → enhanced secretion of K⁺ and H⁺ (leading to hypokalemia and metabolic alkalosis). It also increases excretion of magnesium, phosphate, iodide, and bromide.
- Calcium Sparing: Unlike loop diuretics, thiazides decrease calcium excretion. By depleting intracellular Na⁺ in the DCT, they enhance the activity of the basolateral Na⁺/Ca²⁺ exchanger → increased calcium reabsorption into the blood.
- Paradoxical Effect in Diabetes Insipidus: Mild volume depletion induced by the diuretic → compensatory increase in proximal tubule reabsorption of Na⁺ and water → decreased delivery of water to the distal nephron → overall reduction in polyuria.
Seguridad y advertencias
Contraindicaciones
- Hypersensitivity to thiazides or sulfonamides
- Anuria
- Pregnancy (relative contraindication in otherwise healthy patients with mild edema)
- Dogs with absorptive (intestinal) hypercalciuria (may result in hypercalcemia)
- Renal impairment (due to reduction in GFR)
- Severe electrolyte imbalances (e.g., severe hypokalaemia or hyponatraemia)
Efectos adversos
- Hypokalemia (most common)
- Hypochloremic alkalosis
- Dilutional hyponatremia
- Hypomagnesemia
- Hypercalcemia (hyperparathyroid-like effects)
- Hypophosphatemia
- Hyperuricemia
- Gastrointestinal reactions (vomiting, diarrhea)
- Polyuria
- Hyperglycemia
- Hyperlipidemias
- Orthostatic hypotension
- Hypersensitivity/dermatologic reactions
- Hypokalaemia
- Hyponatraemia
- Hypochloraemia
- Hyperglycaemia
- Volume contraction (dehydration)
- Activation of the renin-angiotensin-aldosterone system (RAAS)
Precauciones
Extreme Caution/Avoid: Severe renal disease, preexisting electrolyte (including hypercalcemia) or water balance abnormalities, impaired hepatic function (may precipitate hepatic coma), hyperuricemia, systemic lupus erythematosus (SLE), or diabetes mellitus.
Monitoring: Patients with conditions that may lead to electrolyte or water balance abnormalities (e.g., vomiting, diarrhea) should be monitored carefully. Chronic therapy requires monitoring of serum potassium.
Laboratory Test Interferences: May increase serum amylase, decrease renal excretion of cortisol, falsely decrease total urinary estrogen, cause false-negative histamine tests for pheochromocytoma, elevate serum calcium (discontinue prior to parathyroid testing), compete for PSP secretion, cause false-negative phentolamine tests, decrease protein-bound iodine, slightly reduce T3 resin uptake, and cause false-negative tyramine tests.
Interacciones farmacológicas
Increased risk for severe hypokalemia
Increased risk for severe hypokalemia
Increased risk for hyperglycemia, hyperuricemia, and hypotension
Thiazide-induced hypokalemia, hypomagnesemia, and/or hypercalcemia may increase the likelihood of digitalis toxicity
Thiazides may increase insulin requirements
Thiazides can increase serum lithium concentrations
Thiazides can alkalinize urine and reduce methenamine effectiveness
Thiazides may increase risk for renal toxicity and NSAIDs may reduce diuretic actions of thiazides
Tubocurarine or other nondepolarizing neuromuscular blocking agents response or duration of effect may be increased
Blocks thiazide-induced uric acid retention (used to therapeutic advantage)
Half-life may be prolonged by thiazides (thiazides can alkalinize the urine)
Hypercalcemia may be exacerbated if thiazides are concurrently administered
Increased risk of developing hypokalaemia.
Synergistic diuresis (sequential nephron blockade) but significantly increased risk of hypokalaemia and dehydration.
Concurrent administration may exacerbate hypercalcaemia.
Concurrent administration may exacerbate hypercalcaemia.
Monitorización
- Serum electrolytes (especially potassium, sodium, chloride, calcium, magnesium)
- Renal function (BUN, Creatinine)
- Hydration status and body weight
- Blood pressure (if treating hypertension)
- Urine output and clinical signs of congestion (if treating heart failure)
- Blood Urea Nitrogen (BUN)
- Serum Creatinine
- Serum Electrolytes (Potassium, Sodium, Chloride, Calcium)
Farmacocinética
Vida media
Absorción
In humans, hydrochlorothiazide is about 65-75% absorbed after oral administration. Onset of diuretic activity occurs in 2 hours; peaks at 4-6 hours.
Distribución
Not specifically described in domestic animals.
Metabolismo
The drug is apparently not metabolized.
Eliminación
Excreted unchanged into the urine. In humans, the serum half-life is approximately 5.6-14.8 hours and duration of activity is 6-12 hours.
Sobredosis
Acute overdosage may cause:
- Electrolyte and water balance problems (hypokalemia, hyponatremia, dehydration)
- CNS effects (ranging from lethargy to coma and seizures)
- GI effects (hypermotility, GI distress)
- Transient increases in BUN
Treatment:
- Empty the gut after recent oral ingestion using standard protocols.
- Avoid concomitant cathartics as they may exacerbate fluid and electrolyte imbalances.
- Monitor and treat electrolyte and water balance abnormalities supportively.
- Monitor respiratory, CNS, and cardiovascular status; treat supportively and symptomatically if required.
Productos disponibles
Formulaciones
- Oral Tablets
- Oral Capsules
- Oral Suspension (Compounded)
- 25 mg hydrochlorothiazide / 2.5 mg amiloride tablets
- 50 mg hydrochlorothiazide / 5 mg amiloride tablets
Veterinario
- None (ARCI Class 4 substance)
Etiquetado para humanos
- Hydrochlorothiazide Oral Tablets: 25 mg, 50 mg, & 100 mg (HydroDIURIL, Hydro-Par, Ezide, generic)
- Hydrochlorothiazide Oral Capsules: 12.5 mg (Microzide, generic)
- Spironolactone/Hydrochlorothiazide Oral Tablets: 25 mg/25 mg & 50 mg/50 mg (Aldactazide, generic)
- Co-amilozide tablets (25 mg hydrochlorothiazide / 2.5 mg amiloride)
- Co-amilozide tablets (50 mg hydrochlorothiazide / 5 mg amiloride)
- Moduretic
Estado regulador
Available as human generic (Co-amilozide) or branded products. 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
Capsules and tablets should be stored at room temperature in well-closed containers. Compounded liquid preparations should be protected from light. A compounded suspension with spironolactone in Ora-Plus/Ora-Sweet retains >90% potency for 60 days at 5°C and 25°C.
Información para el cliente
La hidroclorotiazida (HCTZ) es una "pastilla para el agua" (diurético) que se utiliza para tratar la retención de líquidos, la presión arterial alta, ciertos tipos de cálculos renales (oxalato de calcio) y un trastorno específico del equilibrio hídrico llamado diabetes insípida.
- Aumento de la micción: Es probable que su mascota orine con más frecuencia y en mayores cantidades. Asegúrese de que siempre tenga acceso a agua potable fresca y limpia, a menos que su veterinario haya restringido específicamente su consumo.
- Descansos para ir al baño: Los perros necesitarán salir con más frecuencia para evitar accidentes dentro de casa. Asegúrese de mantener los areneros limpios para los gatos.
- Vigile los desequilibrios: Debido a que este medicamento elimina agua y sales del cuerpo, vigile si hay signos de deshidratación o niveles bajos de potasio. Comuníquese con su veterinario de inmediato si nota:
- Sed excesiva o letargo/debilidad extrema
- Inquietud o confusión
- Vómitos o diarrea (que pueden empeorar la pérdida de líquidos)
- Una disminución repentina en la micción
- Administrar con comida: Si el medicamento le causa malestar estomacal a su mascota, intente administrarlo con una pequeña comida o premio.
- No suspenda el tratamiento abruptamente: Si está tratando una insuficiencia cardíaca o presión arterial alta, no deje de administrar este medicamento sin consultar a su veterinario, ya que los síntomas pueden reaparecer rápidamente.
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.