ThyroVet (levothyroxine sodium 0.2 mg) Dailymed

Description Section

​ThyroVet™

(Levothyroxine Sodium Tablets)

For use in animal only.

Keep out of reach of children.

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

Indications:

For use as thyroid hormone replacement therapy in dogs with hypothyroidism or other condition in which natural thyroid hormone production is insufficient.

Storage:

Protect from light.  Store at 20°-25°C (68°-77°F) with excursions between 15°-30°C (59°-86°F).

Distributed by: MWI

Boise, ID 83705

(888) 694-8381

www.vetone.net

Manufactured by:

Neogen Corporation

Lexington, KY 40511

MADE IN USA

Dosage & Administration:

​Initial dose: 0.1 mg/10 lb (4.5 kg) body weight by mouth twice a day​

​Typical maintenance dose: ​0.1 mg/10 lb (4.5 kg) body weight by mouth once a day.

Blood thyroid hormone levels should be monitored every 2-4 weeks following initial dosing to establish a maintenance dose suitable for the individual patient.  Tablets may be administered orally or placed in food.

Warning:

Administer with caution to animals with primary hypertension, euthyroidism and clinically diagnosed heart disease.  Use in pregnant bitches has not been evaluated.

Package Insert

​VETone®

ThryroVetâ„¢

​LEVOTHYROXINE SODIUM TABLETS, USP

​Caution:

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

​Administration:

For use only in dogs, under the care of a veterinarian.

​Description:

Each Levothyroxine Sodium Tablet provides synthetic crystalline levothyroxine sodium (L-thyroxine).

​Action:

Levothyroxine sodium acts, as does endogenous thyroxine, to stimulate metabolism, growth, development, and differentiation of tissues. It increases the rate of energy exchange and increases 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.  For purposes of comparison, 0.1 mg of levothryoxine sodium elicits a clinical response approximately equal to that produced by one grain (65 mg) of desiccated thyroid.

​Indications:

Provides thyroid replacement therapy in all conditions of inadequate production of thyroid hormones.  Hypothyroidism is the generalized metabolic disease resulting from deficiency of the thyroid hormones levothyroxine (T4) and liothyronine (T3).  Levothyroxine sodium will provide levothryoxine (T4) as a substrate for the physiologic deiodination to liothyronine (T3).  Administration of levothyroxine sodium alone will result in complete physiologic thyroid replacement.

Canine hypothyroidism is usually primary, i.e., due to atrophy of the thyroid gland.  In the majority of cases the atrophy is associated with lymphocytic thyroiditis; in the remainder it is non-inflammatory and of unknown etiology.  Less than 10 percent of cases of hypothyroidism are secondary, i.e., due to deficiency of thyroid stimulating hormone (TSH).  TSH deficiency may occur as a component of congenital hypopituitarism or as an acquired disorder in adult dogs, in which case it is invariably due to the growth of the pituitary tumor.

​Hypothyroidism in the Dog:

Hypothyroidism usually occurs in middle-aged and older dogs, although the condition will sometimes be seen in younger dogs of the larger breeds.  Neutered animals of either sex are also frequently affected, regardless of age.  The following are clinical signs of hypothyroidism in dogs:

Lethargy, lack of endurance, increased sleeping; reduced interest, alertness and excitability; Slow heart rate, weak apex beat and pulse, low voltage on ECG; Preference for warmth, low body temperature, cool skin; Increased body weight; Stiff and slow movements, dragging of front feet; Head tilt, disturbed balance, unilateral facial paralysis; Atrophy of epidermis, thickening of dermis; Surface and follicular hyperkeratosis, pigmentation; Puffy face, blepharoptosis, tragic expression; Dry, coarse, sparse, coat, slow regrowth after clipping; Retarded turnover of hair (carpet coat of boxers); Shortening or absence of estrus, lack of libido; Dry feces, occasional diarrhea; Hypercholesterolemia; Normochromic, normocytic anemia; Elevated serum creatinine phosphokinase.

​Contraindications:

Levothyroxine sodium therapy is contraindicated in thyrotoxicosis, acute myocardial infarction, and uncorrected adrenal insufficiency.  Use in pregnant bitches has not been evaluated.

​Precautions:

The effects of levothyroxine sodium therapy are slow to manifest.  Overdosage of any thyroid drug may produce the signs and symptoms of thyrotoxicosis, including but not limited to polydipsia, polyuria, polyphagia, reduced heat tolderance, and hyperactivity or personality change.  Administer with caution to animal with clinically significant heart disease, hypertension, or other complications for which a sharply increased metabolic rate might prove hazardous.

​Adverse Reactions:

There are no particular adverse reactions connected with L-thyroxine therapy at the recommended dosage levels.  Overdose will result in signs of thyrotoxicosis uled above under Precautions.

​Dosage:

The initial recommended dose is 0.1 mg/10 lb (4.5 kg) body weight twice daily.  Dosage is then adjusted according to patient's response by monitoring T4 blood levels at four-week intervals.  The usual maintenance dose is 0.1 mg/10lb (4.5 kg) once daily.

​Administration:

L-thyroxine tablets may be administered orally or placed in food.

​Dosage forms available:

0.1 mg, 0.2 mg, 0.3 mg, 0.4 mg, 0.5 mg, 0.6 mg, 0.7 mg, 0.8 mg, tablets in bottles of 180 and 1000 ct.  1.0 mg tablets are available in 1000 ct bottles.

​Storage:

Store at 20°-25°C (68°-77°F) with excursions between 15°-30°C (50°-86°F).  Protect from light.

​References:

1. Evinger JV, Nelson RW. ​JAVMA ​19841185 (3):314-316

2.Nelson RW. In Kirk RW, ed. ​Current Veterinary Therapy X. ​Philadelphia: WB Saunders; 1989:994

3. Feldman E, Nelson RW. ​Canine and Feline Endocrinology and Reproduction.  ​Philadelphia: WB Saunders; 1987:82