Endocrine Drugs

Question 1

Primary Hypothyroidism

Answer 1

TSH is working well
Thyroid gland is not working

High or normal TSH + low T4,T3 .

Question 2

Primary treatment in Hypothyroidism

Answer 2

Hormone replacement : Levothyroxine ( synthetic T4) or Liothyronine ( T3 isomer )

Question 3

Drug of choice in primary hypothyroidism (bad thyroid gland)

Answer 3

Synthetic thyroxine (T4) -Levothyroxine

Question 4

Secondary hypothyroidism

Answer 4

Disease in Hypothalamus or the Ant. Pituitary

Both TSH and T4 are low .

Question 5

Goal of therapy for hypothyroidism

Answer 5

1) reach euthyroid state ( Normal TSH and less symptoms )
2) reduce goiter size
3) Prevent thyroid cancer recurrence

Question 6

Which lab to monitor primary hypothyroidism?

Answer 6

TSH

Question 7

Dosage of Levothyroxine in young and healthy

Answer 7

50-200mcg per day

Question 8

Who may need decreased dose of Levothyroxine?

Answer 8

1) Elderly

Question 9

Who may need increased dose of Levothyroxine

Answer 9

Pregnant ( thyroid hormone requirement goes up )

Question 10

1/2 life of Levothyroxine

Answer 10

7 to 10 days- meaning…

Patient will can miss several days of med without adverse consequences

Question 11

If patient NPO how do you give Levothyroxine

Answer 11

Parenterally, give 80% of the usual PO dose

Question 12

T3 Liothyronine

Answer 12

A)- Isomer of T3
B)- 2.5 to 3 times more potent then T4
C) rapid onset + short duration = not good for long term therapy

Question 13

Hyperthyroidism : 3 treatment options

Answer 13

1- Anti-thyroid meds
2- Radioiodine
3- Surgery

Question 14

Measuring TSH in hyperthyroidism

Answer 14

Determines diagnosis but not not degree/severity of disease .

Question 15

Why do we measure T3 T4 in hyperthyroidism?

Answer 15

To assess efficacy of treatment

Question 16

Can TSH be used to assess efficacy of hyperthyroidism treatment ?

Answer 16

Yes. But only once thyroid hormone steady state is achieved .
If TSH start getting too low again ( primary) or too high again (secondary ) treatment needs to be addressed

Question 17

Primary hyperthyroidism

Answer 17

Thyroid gland is making too much
TSH low ( no need to stimulate ) and T3 T4 high

Question 18

Secondary hyperthyroidism

Answer 18

Ant.pituitary or hypothalamus problem. Too much TSH

Both TSH and T3 T4 are elevated

Question 19

High TSH High T3/T4

Answer 19

Secondary hyperthyroidism

Question 20

Low/normal TSH and High T3/T4

Answer 20

Primary Hyperthyrodism

Question 21

What are the anti-thyroids used for hyperthyroidism?

Answer 21

Thianomides : Methimazole ( Tapazole) , PTU
Inhibitor of Iodide Transport
Iodide
Radioactive Iodine

Question 22

Prototype anti-thyroid

Answer 22

PTU

Question 23

Methimazole vs PTU 1/2 life

Answer 23

Methimazole = 4-6 hrs = once a day dosing 
PTU= 75 mins = many times a day dosing

Question 24

Minor S/E of thianomides

Answer 24

Urticaria
Macular skin rash
GI discomfort
Arthralgia

Question 25

Rare but serious S/E of thianomines

Answer 25

Granulocytopenia : marked decrease in granulocytes ( a type of WBC) Agranulocytosis: severe leukopenia Occurs in the 1st 3 month of therapy

Question 26

Earliest sign of agranulocytosis

Answer 26

Pharyngitis and Fever

Question 27

Pharyngitis and Fever in pt receiving Methimazole or PTU :

Answer 27

Agranulocytosis; stop med at first sign for better recovery chance

Question 28

Which Thianomine is preferred in pregnancy and why

Answer 28

Propylthioracil ( PTU) has limited placental crossing .

Question 29

What S/E is associated specifically with PTU?

Answer 29

Hepatotoxicity

Question 30

Which Thianomine can appear in breast milk?

Answer 30

Methimazole ( Tapazole )

Question 31

Iodide as anti- thyroid med :-0 ?????

Answer 31

Yes... it’s a paradoxical treatment , is the oldest anti-thyroid therapy, and it is not fully understood why it works ...(recall Iodide helps make more T3,T4 ..smh!)

Question 32

Most important clinical effect of high dose Iodide

Answer 32

Inhibits release of thyroid hormone

Question 33

Recommended regimen of iodide prior to thyroidectomy?

Answer 33

Oral Potassium Iodide ( decreases thyroid vascularity) and Propanolol

Question 34

S/E of chronic Iodide therapy

Answer 34

Recurrence of previously excessive thyroid gland activity

Question 35

How does Iodide stop TSH release within 24 hr?

Answer 35

Maybe by inhibiting TSH and cAMP

Question 36

Allergic reactions can happen with iodide along with ...

Answer 36

Angiodema and Laryngeal edema

Question 37

Radioactive Iodine aka I-131 can destroy gland In ...

Answer 37

6- 8 weeks Drug so good it may even cause hypothyroidism . Can cure in just 1 dose , some may get 1-2 more doses .

Question 38

I-131 is given on patients with

Answer 38

1) Graves disease | 2) after euthyroidism achieved with Thianomine

Question 39

Peop patient on Radioactive Iodine , think...

Answer 39

Iatrogenic Hypothyroidism | *Iatrogenic( induced by medical intervention)

Question 40

I-131 C/I in pregnancy because

Answer 40

The thyroid of the fetus will concentrate it . ( it’s and isotope btw)