Metyrapone
Also known as: Metopirone
> **Important**: This medication is used to lower the amount of cortisol (stress hormone) your cat's body produces. Because it often needs to be custom-made (compounded) for your cat's specific size, follow the pharmacy's storage instructions carefully. * **Administration**: Give this medication with food to reduce the chance of stomach upset and vomiting. * **Diabetic Cats**: If your cat is also receiving insulin, watch them very closely. As this drug works, your cat's need for insulin may drop dramatically, putting them at risk for low blood sugar (hypoglycemia). Watch for weakness, wobbliness, or seizures. * **When to Call the Vet**: Contact your veterinarian **immediately** if your cat stops eating, seems unusually weak or lethargic, vomits, has diarrhea, or shows changes in drinking or urination. These could be signs that their cortisol levels have dropped too low.
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
How it is given
Possible side effects
- Nausea
- Vomiting
- Abdominal pain
- Headache (reported in humans)
- Dizziness (reported in humans)
- Sedation (reported in humans)
- Allergic rash (reported in humans)
- Bone marrow depression (rare)
Cautions & contraindications
- Known hypersensitivity to metyrapone
- Primary adrenal cortical insufficiency (Addison's disease)
- > **Diabetic Patients**: Use with extreme caution and enhanced monitoring in cats with concurrent diabetes mellitus. As cortisol levels drop, insulin resistance resolves, and **hypoglycemia can develop rapidly** if insulin doses are not adjusted. * **Pregnancy**: FDA Category C. Use in pregnant queens only if clearly needed. Fetal pituitary response to the enzymatic block has been detected in humans. * **Lactation**: Safety is unknown; use with caution. * **Laboratory Interference**: May interfere with diagnostic tests. Antidepressants, antithyroid drugs, phenothiazines, barbiturates, and exogenous hormones can alter metyrapone test results.
Drug interactions
- Acetaminophen: Increased risk for acetaminophen toxicity. Note: Acetaminophen is strictly contraindicated in cats due to fatal methemoglobinemia and hepatotoxicity.
- Corticosteroids: Decreases the efficacy of metyrapone by suppressing ACTH and interfering with the diagnostic or therapeutic intent.
Frequently asked questions
What is Metyrapone used for in pets?
> **Important**: This medication is used to lower the amount of cortisol (stress hormone) your cat's body produces. Because it often needs to be custom-made (compounded) for your cat's specific size, follow the pharmacy's storage instructions carefully. * **Administration**: Give this medication with food to reduce the chance of stomach upset and vomiting. * **Diabetic Cats**: If your cat is also receiving insulin, watch them very closely. As this drug works, your cat's need for insulin may drop dramatically, putting them at risk for low blood sugar (hypoglycemia). Watch for weakness, wobbliness, or seizures. * **When to Call the Vet**: Contact your veterinarian **immediately** if your cat stops eating, seems unusually weak or lethargic, vomits, has diarrhea, or shows changes in drinking or urination. These could be signs that their cortisol levels have dropped too low.
Is Metyrapone 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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