L30: Agents to Treat Endocrine Disorders

Question 1

What radioactive iodine isotope is used for imaging of the thyroid to see if hyperthyroidism is present?

Answer 1

123 Iodine

Question 2

What is the use of 123 Iodine in hyperthyroidism?

Answer 2

used for radioactive imaging of the thyroid

Question 3

What are the 3 main treatment options for treating hyperthyroidism?

Answer 3

1. Radioactive Iodine
2. Surgery (subtotal or total)
3. Thioureylenes

Question 4

What radioactive iodine isotope is used to reducing the level of thyroid hormone in hyperthyroidism?

Answer 4

131 Iodine

Question 5

How does 131 Iodine work in treating hyperthyroidism?

Answer 5

• radioactive isotope taken up and incorporated into thryoglobulin
• emits gamma + beta rays
• exerts cytotoxic action (kills cells)

Question 6

What are some side effects of 131 iodine?

Answer 6

• hypothyroidism

- nausea

Question 7

What is the MOA/effect of thioureylenes in the treatment of hyperthyroidism?

Answer 7

reduces the levels of thyroid hormones

Question 8

What are thioureylenes? Give 3 examples

Answer 8

• used to treat hyperthyroidism
• reduces the levels of thyroid hormones

1. Carbimazole
2. Methimazole
3. Propylthiouracil

Question 9

What class of drugs do Carbimazole and Methimazole belong to? What is their MOA?

Answer 9

Thioureylenes: used to treat hyperthyroidism

MOA = inhibits thyroperoxidase

Question 10

What class of drugs does Propylthiouracil belong to? What is its MOA?

Answer 10

Thioureylenes: used to treat hyperthyroidism

MOA = inhibits thyroperoxidase + inhibits enzyme 5’-deiodinase

Question 11

What is the function of the enzyme 5’-diodinase in thyroid hormone production?

Answer 11

converts T4 to its active form, T3

Question 12

List some of the adverse effects of thioureylenes

Answer 12

• granulocytopenia*
• skin rash; itching
• hair loss
• upset stomach
• loss of taste

Question 13

List 2 adjunctive therapies that may be given to help treat the symptoms of hyperthyroidism. Explain what each treats

Answer 13

1. Beta-Adrenoceptor Antagonists
   - treats tremors, palpitations, heat intolerance, nervousness
   - e.g. Propranolol
2. Corticosteroids
   - anti-inflammatory

Question 14

Give an example of a beta-adrenoceptor antagonist that may be used as adjunctive therapy for hyperthyroidism

Answer 14

Propranolol

Question 15

What is the treatment/medication given to treat hypothyroidism?

Answer 15

Synthetic Thyroxine Derivative

- e.g. Levothyroxine, Liothyronine

Question 16

List some adverse effects of synthetic thyroxine derivatives which are given to treat hypothyroidism

Answer 16

• palpitations
• nervousness
• headache
• difficulty sleeping
• swelling of legs + ankles
• weight loss + increased appetite

Question 17

In hyperparathyroidism, what will happen to the state of a patient’s bones?

Answer 17

increase PTH = increased serum calcium

- leads to osteoporosis (brittle bones)

Question 18

In hypoparathyroidism, what will happen to the state of a patient’s bones?

Answer 18

decrease PTH = decreased serum calcium

- leads to osteomalacia (soft bones)

Question 19

Osteoporosis occurs due to which parathyroid pathology?

Answer 19

hyperparathyroidism

Question 20

Osteomalacia occurs due to which parathyroid pathology?

Answer 20

hypoparathyroidism

Question 21

What are the 2 main treatment options for treating hyperparathyroidism?

Answer 21

1. Surgery

2. Drug Therapies (Calcimimetics, Bisphosphonates, Calcitonin)

Question 22

What is the treatment of choice (first line treatment) of hyperparathyroidism?

Answer 22

Surgery

Question 23

What are calcimimetics? What are they used for?

Answer 23

• used for hyperparathyroidism
• mimics calcium circulating in blood to trick parathyroid to not produce PTH

e.g. Cinacalcet

Question 24

What is Cinacalcet? What is it used for?

Answer 24

Calcimimetic - used to treat hyperparathyroidism

Question 25

What are bisphosphonates? What are they used for?

Answer 25

- used for hyperparathyroidism - inhibits recruitment of osteoclasts (stops bone breakdown) e.g. Alendronate, Risedronate

Question 26

What are Alendronate and Risedronate? What are they used for?

Answer 26

Bisphosphonates | - used for hyperparathyroidism

Question 27

What is calcitonin used for? How does it work? How is it typically given?

Answer 27

- used for hyperparathyroidism - directly inhibits osteoclasts by binding to and inhibiting the calcitonin osteoclast receptor (CtR-Gs) - given via IV

Question 28

List 3 classes of drugs that may be given to treat hyperparathyroidism

Answer 28

1. Calcimimetics 2. Bisphosphonates 3. Calcitonin

Question 29

What adjunctive therapy may be given to help treat the symptoms of hyperparathyroidism?

Answer 29

``` simple analgesics (NSAIDs, ibuprofen, aspirin) - these will treat pain only ```

Question 30

List the 3 possible treatments for hypoparathyroidism

Answer 30

1. Calcium Salts 2. Vitamin D 3. Teriparatide

Question 31

What are Calcium Salts? What are they used for?

Answer 31

- used in hypoparathyroidism - replaces calcium in the body - oral solution (NOT IM)

Question 32

Why can't calcium salts be given intramuscularly?

Answer 32

this will cause extreme contraction of the muscle at te site which is painful will also cause cell death - necrosis

Question 33

List the side effects of calcium salts, a treatment for hypoparathyroidism

Answer 33

- constipation - chronic kidney disease - kidney stones

Question 34

Why is vitamin D used to treat hypoparathyroidism?

Answer 34

- promotes calcium absorption in the intestines | - strengthens bones

Question 35

List some side effects of vitamin D, a treatment for hypoparathyroidism

Answer 35

- allergic skin reactions from build-up of calcium in arteries - changes in cholesterol levels - daytime sleepiness

Question 36

What is Teriparatide? What is it used to treat?

Answer 36

- used to treat hypoparathyroidism - prefilled pen (thigh/abdomen) - recombinant form of PTH - stimulates bone formation + strengthens bone

Question 37

What is the 1 major adverse effect of teriparatide, a drug that is used to treat hypoparathyroidism

Answer 37

osteosarcoma

Question 38

What are 2 contraindications of using Iodine-131?

Answer 38

- pregnancy | - severe Graves' opthalmopathy