Dihidrotaquisterol
Dihydrotachysterol
También conocido como: DHT · Hytakerol · AT 10 · Atiten · Dihydral · Dygratyl · Tachyrol · Tachystin · dichysterol · dihydrotachysterol2
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 |
|---|---|---|---|---|---|
| Hypocalcemia secondary to hypoparathyroidism | Initially give 0.03 mg/kg PO for several days or until effect is demonstrated, then give 0.02 mg/kg for 2 days, then 0.01 mg/kg per day. | PO | q24h | — | 🌎 NA |
- Hypocalcemia secondary to hypoparathyroidism: Pet should remain hospitalized until serum calcium concentration remains stable between 8-9.5 mg/dL. Recheck serum calcium on a weekly basis during early stages of treatment; recheck every 2-3 months long-term. Some dogs and cats that appear to be resistant to treatment on tablets or capsules may respond to the liquid form.
Gatos
| Indicación | Dosis | Vía | Frecuencia | Duración | Región |
|---|---|---|---|---|---|
| Hypocalcemia secondary to hypoparathyroidism | Initially give 0.03 mg/kg PO for several days or until effect is demonstrated, then give 0.02 mg/kg for 2 days, then 0.01 mg/kg per day. | PO | q24h | — | 🌎 NA |
| Chronic hypocalcemia with oral calcium tx | Initially: 0.02-0.03 mg/kg/day PO. Maintenance: 0.01-0.02 mg/kg PO q24-48h. | PO | q24-48h | — | 🌎 NA |
- Hypocalcemia secondary to hypoparathyroidism: Pet should remain hospitalized until serum calcium concentration remains stable between 8-9.5 mg/dL. Recheck serum calcium on a weekly basis during early stages of treatment; recheck every 2-3 months long-term. Some dogs and cats that appear to be resistant to treatment on tablets or capsules may respond to the liquid form.
Las dosis son una referencia clínica para profesionales veterinarios autorizados. Confirme siempre con el prospecto actual y cada paciente individual.
Resumen
El dihidrotaquisterol (DHT) es un análogo sintético de la vitamina D liposoluble utilizado principalmente en medicina veterinaria para el manejo de la hipocalcemia secundaria al hipoparatiroidismo o a la enfermedad renal grave.
Aunque históricamente ha sido importante, su uso clínico ha sido desplazado en gran medida por el calcitriol debido a problemas de disponibilidad comercial y al perfil farmacocinético más favorable del calcitriol (inicio de acción más rápido y duración más corta, lo que facilita el manejo de la hipercalcemia accidental).
Puntos clínicos clave:
- Inicio de acción más rápido que el ergocalciferol (Vitamina D2), pero más lento que el calcitriol.
- Evita la activación renal: A diferencia del colecalciferol, el DHT no requiere la enzima 1-alfa-hidroxilasa en los riñones para activarse, lo que lo hace eficaz en pacientes con insuficiencia renal grave.
- Riesgo de toxicidad: Dado que sus efectos pueden tardar de 1 a 3 semanas en disiparse, la hipercalcemia iatrogénica es un riesgo significativo y requiere un monitoreo diligente.
Mecanismo de acción
Dihydrotachysterol acts as a synthetic analog of 1,25-dihydroxyvitamin D. Its mechanism of action involves several key steps:
- Hepatic Activation: DHT is absorbed from the GI tract and transported to the liver, where it undergoes hydroxylation by hepatic 25-hydroxylase → 25-hydroxydihydrotachysterol (the active metabolite).
- Receptor Binding: The active metabolite binds to Vitamin D Receptors (VDR) in target tissues (primarily intestine, bone, and kidneys).
- Calcium Homeostasis:
- Intestine: Stimulates the synthesis of calcium-binding proteins (e.g., calbindin) → significantly enhances dietary calcium and phosphorus absorption.
- Bone: Works synergistically with parathyroid hormone (PTH) to promote the accretion and resorption of minerals, mobilizing calcium into the extracellular fluid.
- Kidneys: Promotes the reabsorption of calcium by the renal tubules.
Clinical Pearl: Because the active form of DHT is structurally similar to 1,25-dihydroxyvitamin D, it effectively bypasses the need for renal 1-alpha-hydroxylase, an enzyme often deficient in chronic kidney disease.
Seguridad y advertencias
Contraindicaciones
- Pre-existing hypercalcemia
- Vitamin D toxicity
- Malabsorption syndromes
- Abnormal sensitivity to the effects of vitamin D
Efectos adversos
- Hypercalcemia (manifesting as polydipsia, polyuria, anorexia, vomiting, lethargy)
- Nephrocalcinosis (soft tissue mineralization)
- Hyperphosphatemia
Precauciones
Important Warnings
- Hyperphosphatemia: Use with extreme caution. Many clinicians consider hyperphosphatemia or a combined calcium/phosphorus product of >70 mg/dL to be an absolute contraindication due to the risk of metastatic soft tissue mineralization (nephrocalcinosis).
- Renal Dysfunction: Use with extreme caution when receiving the drug for non-renal indications.
- Pregnancy: FDA Category C. Hypervitaminosis D has caused fetal abnormalities in various species. Weigh risks vs. benefits.
- Nursing: Vitamin D is excreted in breast milk in limited amounts; use with caution.
- Laboratory Interference: Serum cholesterol levels may be falsely elevated by vitamin D analogs when using the Zlatkis-Zak reaction.
Interacciones farmacológicas
Use with vitamin D analogs may induce severe hypercalcemia.
Can nullify the calcium-elevating effects of vitamin D analogs.
Patients are highly sensitive to the arrhythmogenic effects of hypercalcemia; intensified monitoring is required.
Patients are sensitive to the effects of hypercalcemia; intensified monitoring is required.
May reduce the amount of DHT absorbed from the GI tract.
May reduce the amount of DHT absorbed from the GI tract.
May reduce the amount of DHT absorbed from the GI tract.
May induce hepatic enzyme systems and increase the metabolism of Vitamin D analogs, thus decreasing their activity.
May induce hepatic enzyme systems and increase the metabolism of Vitamin D analogs, thus decreasing their activity.
May induce hepatic enzyme systems and increase the metabolism of Vitamin D analogs, thus decreasing their activity.
May cause hypercalcemia when given in conjunction with Vitamin D analogs.
Monitorización
- Serum calcium levels (closely/twice daily during initial treatment; at least 2-4 times yearly during maintenance)
- Serum phosphorus levels (particularly in renal failure patients)
- Calcium-phosphorus product (Ca x P)
Farmacocinética
Absorción
Readily absorbed from the small intestine if fat absorption is normal. Bile is required for adequate absorption; patients with steatorrhea, liver, or biliary disease will have diminished absorption. Liquid dosage forms may have better bioavailability than tablets/capsules in some animals.
Distribución
Widely distributed and highly protein-bound in plasma.
Metabolismo
Hydroxylated in the liver to 25-hydroxy-dihydrotachysterol, the active form of the drug. Does not require parathormone activation in the kidneys.
Eliminación
Excreted primarily via bile and feces. Offloads relatively rapidly compared to some other forms of vitamin D, with effects dissipating in 1-3 weeks.
Sobredosis
Acute Toxicity
Acute ingestions should be managed using established protocols for GI decontamination. Orally administered mineral oil may reduce absorption and enhance fecal elimination.
Chronic Toxicity (Hypercalcemia)
Hypercalcemia secondary to chronic dosing is a serious complication.
- Discontinue Therapy: Immediately stop DHT and any exogenous calcium supplementation.
- Severe Hypercalcemia Management: Administer furosemide, calcium-free IV fluids (e.g., 0.9% normal saline) to promote diuresis, urine acidification, and corticosteroids (which decrease intestinal calcium absorption and increase renal excretion).
- Monitoring: Because of the long duration of action of DHT (usually one week and potentially up to 3 weeks), hypercalcemia may persist for an extended period.
- Re-initiation: Restart DHT/calcium therapy at a reduced dosage with diligent monitoring only when serum calcium levels return to the normal range.
Productos disponibles
Formulaciones
- Tablets (compounded)
- Capsules (compounded)
- Oral liquid/concentrate (compounded)
Veterinario
- None commercially available (must be compounded)
Etiquetado para humanos
- None commercially available (must be compounded)
Estado regulador
Sin datos reguladores para: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Almacenamiento y estabilidad
Store at room temperature (15-30°C). Capsules or tablets should be stored in well-closed, light-resistant containers. Oral concentrate should be stored in tight, light-resistant containers.
Información para el cliente
Información importante para los propietarios de mascotas
El dihidrotaquisterol (DHT) es un medicamento utilizado para ayudar al cuerpo de su mascota a absorber y mantener niveles normales de calcio, generalmente porque sus glándulas paratiroides o sus riñones no funcionan correctamente.
- Dosificación estricta: Administre este medicamento exactamente como se le ha recetado. Nunca cambie la dosis ni administre suplementos de calcio adicionales sin instrucciones explícitas de su veterinario. Incluso cambios pequeños pueden causar alteraciones peligrosas en los niveles de calcio en sangre.
- Signos de calcio alto (Hipercalcemia): Esté atento a un aumento de la sed (beber más agua), aumento de la micción, pérdida de apetito, vómitos o letargo severo. Comuníquese con su veterinario de inmediato si nota estos signos.
- Signos de calcio bajo (Hipocalcemia): Si la dosis es demasiado baja, su mascota puede mostrar signos de calcio bajo, incluyendo temblores musculares, espasmos faciales, rigidez, debilidad, falta de coordinación al caminar (ataxia), cambios de comportamiento o convulsiones.
- Análisis de sangre frecuentes: Su mascota necesitará análisis de sangre frecuentes, especialmente al comenzar el medicamento, para asegurar que sus niveles de calcio sean seguros. Esto es obligatorio para su seguridad.
- Administración: Si su mascota no responde bien a las pastillas, su veterinario puede cambiarla a una forma líquida, la cual a veces se absorbe mejor.
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.