Leventa Solution

Generic name: levothyroxine sodium solution
Dosage form: FOR ANIMAL USE ONLY

Disclaimer: This drug has not been found by FDA to be safe and effective, and this labeling has not been approved by FDA.

Each mL of LEVENTA® (levothyroxine sodium, U.S.P.) oral solution provides 1 mg synthetic crystalline levothyroxine sodium (L-thyroxine).

CAUTION

Federal law restricts this drug to use by or on the order of a licensed veterinarian.

INDICATION

Thyroid replacement therapy in dogs with hypothyroidism. Hypothyroidism is the generalized metabolic disease resulting from deficiency of the thyroid hormones, L-thyroxine (T4) and triiodothyronine (T3). LEVENTA® oral solution will provide L-thyroxine (T4) as a substrate for the physiologic deiodination to triiodothyronine (T3). Administration of L-thyroxine (T4), identical to the L-thyroxine (T4) secreted endogenously by the normal thyroid gland, will result in complete physiologic thyroid replacement. L-thyroxine (T4) acts to stimulate metabolism, growth, development and differentiation of tissues. It increases the rate of energy exchange and the maturation rate of the epiphyses.

The clinical diagnosis of hypothyroidism should be completed by evaluation of the thyroid hormone of the dog, i.e. measurement of serum levels of total (or preferably free) thyroxine (T4) and thyroid stimulating hormone (TSH). A low total (or free) T4 concentration combined with high TSH concentration is strongly suggestive for primary hypothyroidism.

PHARMACOLOGY

Levothyroxine sodium acts, as does endogenous L-thyroxine (T4), to stimulate metabolism, growth, development and differentiation of tissues. It increases the rate of energy exchange and the maturation rate of the epiphyses. Levothyroxine sodium is absorbed rapidly from the gastrointestinal tract after oral administration. Following absorption, the compound becomes bound to the serum alpha globulin fraction.

DOSAGE

The adequate dose rate has to be defined individually for each dog. Treatment should be initiated at a recommended dose rate of 20 µg L-thyroxine/kg once daily and re-evaluated every 4 weeks by monitoring T4 serum levels 4 to 6 hours post-treatment. According to the T4 levels, the veterinarian will decide to adjust the dose rate if needed. Once the dosage suitable to solve the hypothyroidism clinical and hormonal condition of the dog is determined (maintenance dosage), serum T4 levels 4 to 6 hours post-treatment should be checked every 6 months. The usual maintenance dosage 20 µg L-thyroxine/kg once daily.

ADMINISTRATION

Remove child resistant cap and insert oral dosing syringe into the plastic push-in adapter. Invert bottle and gently draw back syringe plunger to the desired dose. Return the bottle to the upright ...