1. VETE Pharmacology& Pharmacy Angela Culp RVT
Hypothyroidism using drug Soloxine

2. Cosmo Chapman 6 yr NM Labrador Retriever
History & Diagnosis
6 yr NM Labrador Retriever
Presented with weight gain and lethargy
Owner noticed massive weight gain and patient wasn’t eating more food.
Wt 59.6 lb 2012
Wt 72.9 lb 2013
Diagnosis: Hypothyroidism

3. Cosmo Chapman Laboratory Finding in 2013 CBC Chemistry
Neutrophils > 80%
Eosinophils < 1%
Chemistry
ALT > 179 IU/L
ALK Phos > 754 IU/L
GGT > 20 IU/L
BUN/ Creat Ratio >28
Cholesterol >412 mg/dl
Total T4 <0.5
Free T4 < 2.2 pmol/L
< Low and > High

4. Definition of Hypothyroidism
Hypothyroidism: abnormally low activity of the thyroid gland in dogs.

5. Dosage of Soloxine
Use a trade name product. Initially give 20 micrograms/kg (0.02 mg/kg) body weight PO twice daily with a maximum dose of 0.8 mg twice daily. Four to eight weeks later evaluate clinical response and draw a T4 level 4–6 hours post dosing.
Cosmo’s RX: 1 T of 0.8 mg po q 12 hr

6. Hypothyroidism and Levothyroxine Sodium; SoloxineR
Soloxine is a drug used to help the body speed up the metabolism and help with the utilization of the glycogen storage.

7. Levothyroxine Sodium; SoloxineR How the drug is metabolized?
Deiodination:
the removal of iodine from a compound (as a thyroid hormone)
Glucuronidation:
an enzyme that hydrolyzes a glucuronide; especially : one that occurs widely (as in the liver and spleen) and hydrolyzes the beta form of a glucuronide
Enterohepatic:
of or involving the intestine and the liver <enterohepatic circulation of bile salts>
The primary pathway of thyroid hormone metabolism is through sequential deiodination. The liver is the main site where both T3 and T4 are metabolized, with T4 deiodination occurring at several other sites, including the kidneys. In addition to deiodination, thyroid hormones are also metabolized through conjugation and glucuronidation and excreted directly into the bile and the gut where they undergo enterohepatic recirculation.

8. Levothyroxine Sodium; SoloxineR How is the drug eliminated from the body?
Half-life elimination is 6-7 days for euthyroid patients; 9-10 days for hypothyroid patients; 3-4 days for hyperthyroid patients. Thyroid hormones are primarily eliminated by the kidneys (approximately 80%), with urinary excretion decreasing with age. The remaining 20% of T4 eliminated in the stool.

9. Levothyroxine Sodium; SoloxineR Explain the drug
This drug is an agonist.
This means that the drug soloxine causes a biological response.
a synthetic thyroid hormone that is chemically identical to thyroxine (T4), which is naturally secreted by the follicular cells of the thyroid gland.

10. Conclusion
After 5 weeks on the drug Soloxine Cosmo returned to have a recheck T4 and Free T4. His vitals had returned to normal and is to be tested annually with his exam to monitor his levels.

11. References LEVOTHYROXINE SODIUM
Plumb, Donald ( ). Plumb's Veterinary Drug Handbook (Kindle Locations ). PharmaVet inc. Kindle Edition.