Dihydrotachysterol
Also known as: DHT, Hytakerol, AT 10, Atiten, Dihydral, Dygratyl, Tachyrol, Tachystin
### Important Information for Pet Owners **Dihydrotachysterol (DHT)** is a medication used to help your pet's body absorb and maintain normal levels of calcium, usually because their parathyroid glands or kidneys are not functioning properly. * **Strict Dosing**: Give this medication exactly as prescribed. **Never** change the dose or give extra calcium supplements without explicit instructions from your veterinarian. Even small changes can cause dangerous shifts in blood calcium levels. * **Signs of High Calcium (Hypercalcemia)**: Watch closely for increased thirst (drinking more water), increased urination, loss of appetite, vomiting, or severe lethargy. Contact your vet immediately if you notice these signs. * **Signs of Low Calcium (Hypocalcemia)**: If the dose is too low, your pet may show signs of low calcium, including muscle tremors, facial twitching, stiffness, weakness, uncoordinated walking (ataxia), behavioral changes, or seizures. * **Frequent Blood Tests**: Your pet will need frequent blood tests, especially when starting the medication, to ensure their calcium levels are safe. This is mandatory for their safety. * **Administration**: If your pet is not responding well to pills, your vet may switch them to a liquid form, which is sometimes absorbed better.
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
What it is used for
- Hypocalcemia secondary to hypoparathyroidism
- Chronic hypocalcemia with oral calcium tx
- Hypocalcemia secondary to hypoparathyroidism
How it is given
Possible side effects
- Hypercalcemia (manifesting as polydipsia, polyuria, anorexia, vomiting, lethargy)
- Nephrocalcinosis (soft tissue mineralization)
- Hyperphosphatemia
Cautions & contraindications
- Pre-existing hypercalcemia
- Vitamin D toxicity
- Malabsorption syndromes
- Abnormal sensitivity to the effects of vitamin D
- ### 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.
Drug interactions
- Calcium-containing phosphorus binding agents (e.g., calcium carbonate): Use with vitamin D analogs may induce severe hypercalcemia.
- Corticosteroids: Can nullify the calcium-elevating effects of vitamin D analogs.
- Digoxin: Patients are highly sensitive to the arrhythmogenic effects of hypercalcemia; intensified monitoring is required.
- Verapamil: Patients are sensitive to the effects of hypercalcemia; intensified monitoring is required.
- Mineral oil: May reduce the amount of DHT absorbed from the GI tract.
- Sucralfate: May reduce the amount of DHT absorbed from the GI tract.
- Cholestyramine: May reduce the amount of DHT absorbed from the GI tract.
- Phenytoin: May induce hepatic enzyme systems and increase the metabolism of Vitamin D analogs, thus decreasing their activity.
- Barbiturates: May induce hepatic enzyme systems and increase the metabolism of Vitamin D analogs, thus decreasing their activity.
- Primidone: May induce hepatic enzyme systems and increase the metabolism of Vitamin D analogs, thus decreasing their activity.
Frequently asked questions
What is Dihydrotachysterol used for in pets?
### Important Information for Pet Owners **Dihydrotachysterol (DHT)** is a medication used to help your pet's body absorb and maintain normal levels of calcium, usually because their parathyroid glands or kidneys are not functioning properly. * **Strict Dosing**: Give this medication exactly as prescribed. **Never** change the dose or give extra calcium supplements without explicit instructions from your veterinarian. Even small changes can cause dangerous shifts in blood calcium levels. * **Signs of High Calcium (Hypercalcemia)**: Watch closely for increased thirst (drinking more water), increased urination, loss of appetite, vomiting, or severe lethargy. Contact your vet immediately if you notice these signs. * **Signs of Low Calcium (Hypocalcemia)**: If the dose is too low, your pet may show signs of low calcium, including muscle tremors, facial twitching, stiffness, weakness, uncoordinated walking (ataxia), behavioral changes, or seizures. * **Frequent Blood Tests**: Your pet will need frequent blood tests, especially when starting the medication, to ensure their calcium levels are safe. This is mandatory for their safety. * **Administration**: If your pet is not responding well to pills, your vet may switch them to a liquid form, which is sometimes absorbed better.
Is Dihydrotachysterol safe for my pet?
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
This article is for general education and is not a substitute for professional veterinary advice. If your pet is unwell, please consult a veterinarian.
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