Pharmacology: Thyroid II Flashcards Preview

Module 6: Repro/Endocrine > Pharmacology: Thyroid II > Flashcards

Flashcards in Pharmacology: Thyroid II Deck (14):
1

What are the possible treatments for myxedema?


Myxedema = Hypothyroidism

- Thyroid USP: dried, defatted thyroids from pig & sheep
unpredictable strength

- Thyroglobulin

- Sodium levothyroxine: T4 = drug of choice

- Sodium liothyronine: T3; used for myxedema coma

- Liotrix

2

What are drug treatment options for hyperthyroidism?  MOA?


Thioamides:

Propylthiouracil

Methimazole

Carbimazole (in UK)

--> MOA: inhibiting Thyroid Peroxidase ==> prevents iodizatiion of thyroglobulin and production of T3 and T4

3


What are the toxicities of thioamides?


Caution in pregnancy:
- Both PTU and methimazole cross placenta; use lowest possible dose

- Thioamides cross into mother's milk

Rare cases of agranulocytosis

4

How is a "thyroid storm" treated?


Thyroid storm is due, in large part, to supersensitization of b-adrenergic receptors
--> Treat immediately with b-blockers:
Propanolol
Atenolol

 

--> Long term treatment with thioamides (PTU, methimazole)

5

What is the premise of readioactive iodide treatment?


In theory, in the case of toxic nodular adenoma, the adenoma takes up the radioactive iodine while the quiescent normal tissue takes up less

--> In practice, it usually desetroys most of the thyroid

--> Must replace loss of thyroid hormone with levothyroxine

**NEVER use 131I during pregnancy!*

6

What is the drug of choice to treat hyperthyroidism?


Radioactive iodine

7

What is the treatment for hypoparathyroidism?


Problem: Low PTH (low serum Ca, high serum phosphate)
- can lead to tetany, convulsions, and death

Treatmetn:

1,25(OH)2D3 and dietary Ca2+ supplement

8

What is the treatment for pseudohypoparathyroidism?


Problem: PTH is elevated, but Ca2+ is lwo
--> often the G-protein Gs is low or abnormal
--> PTH fails to stimulate 1a hydroxylase activty in the kidney

Treatment: 1,25(OH)2D3

9

What is the treatmet for Rickets?


Problem: lack of sufficient sunlight --> insufficient D3 to make 1,25(OH)2D3
- Increased PTH --> Ca removal from bones --> bones become soft

Treatment: sunlight
food supplemented with vit. D2 or D3

 

10

What is the treatment for Vitamin D-Dependent Rickets?


Problem: abnormal 1a-hydroxylase in kidney
- autosomal recessive
- sun exposure is not effective

Treatment: 1,25(OH)2D3

11

What is the treatment for drug-induced osteopenia?


Problem - Certain drugs interfere with Ca absorption from gut
- pheytoin
- phenobarbital
- glucocorticoids

Treatment: Vitamine 25(OH)D3, D2, or D3

12

What is the treatment for Paget's Disease?


Problem: overactivity of osteoclasts leads to abnormal restructuring of bone - patients prone to compression fractures

Treatment: Calcitonin or bisphosphonates

13


What are examples of bisphosphonates?


Elondronate

Risedronate

Sodium Etidronate

Pamidronate

Ibandronate

Zoledronic acid

14

What are the treatment options for post-menopausal osteoporosis?


Estrogen

SERMs (raloxifene)

Bisphosphonates (Alendronate)

Teriparatide (active portion of PTH) - daily subcut. injection

Denosumab - anti-RANKL monocloonal Ab (mimics OPG)