Levothyroxine
Also known as: Leventa, Soloxine, Thyforon
Give this medication consistently, ideally at the same time each day and consistently with or without food. **Do not change brands** without consulting your veterinarian, as different brands may be absorbed differently. Watch for signs of receiving too much medication, such as excessive panting, restlessness, increased thirst, or increased urination. This medication is usually required for the rest of your pet's life, and regular blood tests are necessary to ensure the dose is correct.
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
- Hypothyroidism
- Hypothyroidism
How it is given
Possible side effects
- Tachycardia
- Excitability
- Nervousness
- Excessive panting
- Unmasking of Addison's disease
Cautions & contraindications
- Uncorrected adrenal insufficiency (Addison's disease)
- Acute myocardial infarction (general precaution)
- Use with caution in patients with **pre-existing cardiac disorders**; lower initial doses are required. Monitor diabetic patients carefully during the initiation of therapy as insulin requirements may change. Many drugs may affect thyroid function tests, which can complicate therapeutic monitoring.
Drug interactions
- Catecholamines: Actions of catecholamines are enhanced by thyroxine
- Sympathomimetics: Actions of sympathomimetics are enhanced by thyroxine
- Insulin: Altered insulin requirements; monitor carefully during initiation of therapy
- Oestrogens: May increase thyroid requirements by increasing thyroxine-binding globulin
- Ciclosporin: Therapeutic effect may be reduced by thyroid hormones
- Digoxin: Therapeutic effect may be reduced by thyroid hormones
- Digitoxin: Therapeutic effect may be reduced by thyroid hormones
- Ketamine: Tachycardia and hypertension may develop when given to patients receiving thyroid hormones
Frequently asked questions
What is Levothyroxine used for in pets?
Give this medication consistently, ideally at the same time each day and consistently with or without food. **Do not change brands** without consulting your veterinarian, as different brands may be absorbed differently. Watch for signs of receiving too much medication, such as excessive panting, restlessness, increased thirst, or increased urination. This medication is usually required for the rest of your pet's life, and regular blood tests are necessary to ensure the dose is correct.
Is Levothyroxine 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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