LEC 2 - Thyroid Hormones + Anti-Thyroid Hormones Flashcards Preview

Pharmacology II > LEC 2 - Thyroid Hormones + Anti-Thyroid Hormones > Flashcards

Flashcards in LEC 2 - Thyroid Hormones + Anti-Thyroid Hormones Deck (31):
1

What are the two hormones that the thyroid release?

T4/T3

Calcitionin

2

What cells release T4/T3?

Follicle cells

3

What cells release calcitonin?

C Cells

4

What is the process by which T4/T3 get into the blood stream?

Iodine comes from blood via Na+ channel then pendrin 

Thyroid peroxidase puts I- onto thyroglobulin 

Carries T3/T4 into cytoplasm

Broken down by lysosome 

5

What are the neuroendocrine effects of TH?

Increased sensitivity of SNS stimulation 

Increased stimulation of all other endocrine organs 

 

6

What are the cardiac effects of TH?

Increased CO 

via HR + contractility + BP

7

What are the respiratory/metabolic effects of TH?

Increased O2 + energy consumption 

Increased erythropoiesis leading to O2 delivery 

8

What are the regulatory hormones of the thryoid?

TRH 

-- and -- 

TSH 

9

Diagnostics: Hypothyroid

decreased T4 

Increased TSH 

10

Diagnostics: Hyperthyroid

Increased T4 

Decreased TSH 

11

What are the four effects of TSH?

Stimulate Iodine symport (NIS) 

Activates thyroglobulin synthesis 

Activates throid peroxidase 

Stimulates lysosomal breakdown of Thyroglobulin 

12

What are the signs a dog is hypothyroid?

Alopecia 

Lethargy 

Overall sad appearance

13

What are the four major reasons for hypothryoidism?

Lymphocytic thyroiditis 

Congenital 

Nutritional status/Underlying disease

Drug-induced

14

What drugs can induce hypothyroidism?

Trimehtoprim/sulfonamides 

Glucocorticoids

Phenobarbital 

15

Which of the drugs that cause hypothyroidism cause there to actually be clinical symptoms?

Trimethoprim/sulfonamides 

16

What is the drug for hypothyroid?

Levothyroixine 

17

How is levo absorped/given?

Orally 

Bioavaliblity decreased with food 

18

How is levo handled in the body?

Most bound to plasma protein 

19

How is levo metabolized?

Hepativ 

Glucoronnylation 

Sulfation 

Deamination 

20

What are the contrindications for levo?

Thyrotoxicosis 

Acute myocardial infarction 

Untreated adrenal insufficency 

21

What are the adverse side effects of levo?

Iatrogenic hyperthyroidism

erythema multiforme

22

What are the signs of hyperthryoid in a cat?

Weight loss with atrophy 

PU/PD

Hyperactive 

Can feel thyroid lobes

23

What can cause adenomatous hyperplasia of the thyroid?

Associated with altered signaling sensivity to TSH 

High levels of dietary Iodine/soy may be the cause

24

When starting to treat a cat with hyperthyroid what is important to remember?

Unmasking CKD in older cats 

Increased CO leads to better perfusion of the kidneys, therefor increased GFR 

25

What are the signs of renal failure?

Increased: 

Creatinine 

BUN

26

What is the drug of choice for hyperthyroid? Where does it work?

Methimazole 

Inhibits production of Thyroid peroxidase 

Inhibits binding of T4/T3 to Thyroglobulin 

27

How is methimazole given?

PO 

or 

Transdermally 

28

What are the adverse effects of methimazole?

Unmasking CKD 

Forming anti-nuclear bodies 

Vomiting/Lethargy 

Thrombocytopenia/Leukopenia 

Hepatopathy 

29

What should be done if you are seeing GI effects of methimazole?

Give transdermally 

30

What is the rate at which methimazole works?

SLOW 

takes 3 to 4 weeks to normalize T4 levels 

31

How is I131 used?

Irreversible treatment of hyperthryoid 

Destroys the cells but aren't powerful enough to destroy C cells