Liothyronine (T3, l-Tri-iodothyronine)

Liothyronine In Dogs & Cats: Uses, Dosage and Side Effects

Overview

• Increases T3 concentrations.

Uses of Liothyronine 

• Diagnosis of feline hyperthyroidism (T3 suppression test).
• Suggested in the treatment of canine hypothyroidism where levothyroxine has been unsuccessful; however, evidence is scant.

Dose of Liothyronine in Dogs and Cats

Dogs:

• Hypothyroidism: 2–6 μg (micrograms)/kg p.o. q8–12h.

Cats:

• T3 suppression test: administer 20 μg (micrograms)/cat p.o. q8h for 7 doses.

Side Effects of Liothyronine in Dogs and Cats

• Signs of overdosage include tachycardia, excitability, nervousness and excessive panting.

Contraindications of Liothyronine in Dogs and Cats

• No information is available.

Some Notes:

• The actions of catecholamines and sympathomimetics are enhanced by thyroxine.
• Diabetic patients receiving thyroid hormones may have altered insulin requirements;
  monitor carefully during the initiation of therapy.
• Oestrogens may increase thyroid requirements by increasing thyroxine-binding
  globulin.
• The therapeutic effect of digoxin may be reduced by thyroid hormones.
• In addition, many drugs may affect thyroid function tests and therefore monitoring of therapy.