Trilostane
Also known as: Vetoryl, Modrastane, Desopan, Modrenal
Trilostane is a highly effective medication for managing Cushing's disease, but it requires careful handling and monitoring. **Handling Precautions:** * **Keep out of reach of children and pets.** * **Pregnancy Warning:** Women who are pregnant or trying to conceive should **NOT** handle these capsules, as the drug can affect human pregnancies. * Wash your hands thoroughly after handling the medication. * Do not open, empty, or attempt to divide the capsules. **Administration:** * Give the medication exactly as prescribed, ideally **with food** to enhance absorption. * Understand that this medication is a **treatment, not a cure**. Your pet will likely need this medication for the rest of their life. **What to Watch For:** * During the first few days, mild lethargy or a decrease in appetite can occur as your pet's body adjusts to lower steroid levels. * **STOP the medication and contact your veterinarian immediately** if your pet experiences severe lethargy, vomiting, diarrhea, collapse, or completely stops eating. These can be signs that the cortisol levels have dropped too low (an Addisonian crisis).
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
- Hyperadrenocorticism
- Hyperadrenocorticism
- Hyperadrenocorticism
- Equine Cushing's syndrome
- Hyperadrenocorticism (HAC) - Label Dose
- Hyperadrenocorticism (HAC) - Alternative Protocol
- Hyperadrenocorticism (HAC) - Low Dose Protocol
- Alopecia X (Alaskan Malamutes)
- Alopecia X (Miniature poodles and Pomeranians)
- Hyperadrenocorticism
How it is given
Possible side effects
- Lethargy
- Inappetence
- Vomiting
- Diarrhea
- Mild electrolyte abnormalities (hyponatremia, hyperkalemia)
- Iatrogenic hypoadrenocorticism (Addisonian crisis)
- Adrenal necrosis (rare but potentially fatal)
- Mild gastrointestinal signs
- Mild increases in serum potassium, bilirubin, and calcium
- Clinical hypoadrenocorticism (Addisonian crisis)
- Adrenal necrosis
- Adrenal hyperplasia (with prolonged treatment)
- Prolonged adrenal suppression after drug withdrawal
Cautions & contraindications
- Hypersensitivity to trilostane
- Pregnancy (reduces progesterone synthesis)
- Use with caution in patients with renal impairment
- Use with caution in patients with hepatic impairment
- Renal insufficiency
- Hepatic insufficiency
- Trilostane is contraindicated in pregnant dogs and should be used with caution in lactating animals. It should be used cautiously in patients with pre-existing renal or hepatic impairment. **Important:** Trilostane does not shrink adrenal tumors; adrenal glands may actually increase in size during therapy due to loss of negative feedback. **Human Safety Warning:** Trilostane is an FDA Category X drug (contraindicated in pregnancy). Pregnant women or women trying to conceive must **not** handle the capsules.
Drug interactions
- ACE Inhibitors (e.g., benazepril, enalapril): Could increase risk for hyperkalemia
- Aminoglutethimide: May potentiate the effects of trilostane and lead to hypoadrenocorticism
- Ketoconazole: May potentiate the effects of trilostane and lead to hypoadrenocorticism
- Mitotane: May potentiate the effects of trilostane and lead to hypoadrenocorticism
- Potassium-sparing diuretics (e.g., spironolactone): Could increase risk for hyperkalemia
- Potassium supplements / High potassium foods: Could increase risk for hyperkalemia
- Itraconazole: Concurrent suppression of adrenal function
Frequently asked questions
What is Trilostane used for in pets?
Trilostane is a highly effective medication for managing Cushing's disease, but it requires careful handling and monitoring. **Handling Precautions:** * **Keep out of reach of children and pets.** * **Pregnancy Warning:** Women who are pregnant or trying to conceive should **NOT** handle these capsules, as the drug can affect human pregnancies. * Wash your hands thoroughly after handling the medication. * Do not open, empty, or attempt to divide the capsules. **Administration:** * Give the medication exactly as prescribed, ideally **with food** to enhance absorption. * Understand that this medication is a **treatment, not a cure**. Your pet will likely need this medication for the rest of their life. **What to Watch For:** * During the first few days, mild lethargy or a decrease in appetite can occur as your pet's body adjusts to lower steroid levels. * **STOP the medication and contact your veterinarian immediately** if your pet experiences severe lethargy, vomiting, diarrhea, collapse, or completely stops eating. These can be signs that the cortisol levels have dropped too low (an Addisonian crisis).
Is Trilostane 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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