Hypothyroidism

Question 1

most common cause

Answer 1

Hashimoto’s disease

Question 2

hypothyroidism results in

Answer 2

generalized slowing down of metabolic process

Question 3

in Hashimoto’s B and T cells

Answer 3

infiltrate the gland as a result of genetic or environmental changes

Question 4

B and T cell infiltration results in

Answer 4

cell destruction by necrosis or induced apoptosis

Question 5

atrophic thyroiditis

Answer 5

cytokines released by T cells as well as native thyroid cells propagate the destructive process

Question 6

cytokine therapy (IFN-alpha) is associated with

Answer 6

increase autoimmune thyroid disease

Question 7

what antibodies are present in atrophic thyroiditis

Answer 7

antibodies to TPO and thyroglobulin (useful markers of disease), possible TSH antibodies also

Question 8

TSH receptor antibodies in atrophic thyroiditis

Answer 8

prevent stimulation of TSH

Question 9

iatrogenic hypothyroidism follows

Answer 9

exposure to radiation or surgery for treatment of hyperthyroidism or head and neck cancers

Question 10

iatrogenic hypothyroidism usually occurs within

Answer 10

3-12 months after I131 and within 1 month of the following surgery

Question 11

most common cause of hypothyroidism worldwide

Answer 11

iodine deficiency

Question 12

pituitary disease and hypothalamic disease can cause

Answer 12

secondary hypothyroidism

Question 13

an increase in TSH is

Answer 13

the first sign of primary hypothyroidism

Question 14

T3 levels in hypothyroidism

Answer 14

will often remain in the normal level despite decreased T4

Question 15

primary hypothyroidism lab values

Answer 15

increased TSH

decreased T4

Question 16

secondary hypothyroidism lab values

Answer 16

normal to decreased TSH

decreased T4

Question 17

subclinical hypothyroidism lab values

Answer 17

mildly increased TSH

normal T4

Question 18

levothyroxine

Answer 18

its synthetic T4, results in a pool thyroid hormone that is readily and consistently converted to T3

Question 19

levothyroxine is DOC because

Answer 19

chemically stable, low cost, no antigenicity, and uniform potency

Question 20

half life of levo

Answer 20

7 days

Question 21

absorption of levo

Answer 21

40-80%, effected by food and some medications

Question 22

distribution of levo

Answer 22

predominantly protein bound

Question 23

contraindications of levothyroxine

Answer 23

untreated thyrotoxicosis, acute MI, and untreated adrenal insufficiency

Question 24

precautions of levothyroxine

Answer 24

NTI, elderly, CV disease, and mucosal disease

Question 25

levothyroxine drug interactions - increased absorption from GI tract

Answer 25

cholestyramine, calcium carbonate, sucralfate, aluminum hydroxide, ferrous sulfate, dietary fiber supplements

Question 26

levothyroxine drug interactions - increased T4 clearance

Answer 26

carbamazepine, phenytoin

Question 27

levothyroxine drug interactions - blocked conversion of T4 to T3

Answer 27

amiodarone

Question 28

IV dosage forms of levothyroxine

Answer 28

200 mcg and 500 mcg vials

Question 29

IV to PO conversion of levothyroxine

Answer 29

IV * 1.33

Question 30

new dose of levothyroxine at about

Answer 30

every 12 mcg

Question 31

levothyroxine average maintenance dose for most adults around

Answer 31

125 mcg/day

Question 32

levothyroxine starting dose for healthy adults

Answer 32

50 mcg/day; increase by 25-50 mcg q6-8 weeks

Question 33

levo; most recent guidelines suggest

Answer 33

1.6 mcg/kg/day as a starting dose in younger, healthy people

Question 34

levo starting dose for elderly

Answer 34

25 mcg/day; increase by 12.5-25 mcg

Question 35

levo dose requirements may increase during _____ and decrease _____

Answer 35

pregnancy; with age

Question 36

levothyroxine should be

Answer 36

taken on an empty stomach and separated from other medicates by at least one hour

Question 37

complete resolution of symptoms may take

Answer 37

several months, should see improvement in 2-3 weeks

Question 38

liothyronine

Answer 38

synthetic T3

Question 39

liothyronine is generally reserved for

Answer 39

myxedema or nontoxic goiter - when rapid therapy is needed to rapidly suppress TSH

Question 40

disadvantages of liothyronine

Answer 40

short half life - fluctuations in hormone concentrations; divided daily dosing usually required higher incidence of cardiac adverse effects

Question 41

Liotrix

Answer 41

attempts to mimic natural secretion; 4:1 ratio of T4:T3

Question 42

disadvantages in liotrix

Answer 42

expensive, lack of therapeutic rationale, not used anymore

Question 43

desiccated thyroid is extracted from

Answer 43

hog, beef, or sheep thyroid gland

Question 44

desiccated thyroid is generally reserved for

Answer 44

those who insist on natural product or feel that synthetic levothyroxine has stopped working for some reason

Question 45

disadvantages of desiccated thyroid

Answer 45

standardized but unpredictable amount of hormone in each tablet, unpredictable patient response, may be antigenic in allergic or sensitive patients

Question 46

monitor TSH at least

Answer 46

q6-8 weeks until patient is euthyroid, then at least annually

Question 47

FT4 can be used to determine

Answer 47

adherence or malabsorption

Question 48

TSH and monitoring

Answer 48

not helpful in monitoring patients with secondary hypothyroidism

Question 49

subclinical hypothyroidism

Answer 49

patients may or may not present with symptoms, guidelines recommend to treat only if patient is experiencing symptoms

Question 50

hypothyroidism during pregnancy leads to

Answer 50

increased rate of still-births and possibly lower psychological scores in infants born by women with inadequate thyroid hormones

Question 51

thyroid hormones must come from mother during

Answer 51

first 2 months of gestation

Question 52

pregnancy dosing of levothyroxine

Answer 52

may increase as much as 25-50%

Question 53

pregnancy and TSH

Answer 53

TSH should be monitored, minimally, at the end of the first and second trimester

Question 54

myxedema coma

Answer 54

end stage of uncontrolled hypothyroidism, needs to be treated in ICU and has a mortality of 60-70%

Question 55

clinical features of myxedema coma

Answer 55

hypothermia, advanced stages of hypothyroid symptoms, delirium/coma

Question 56

patients with myxedema coma usually require

Answer 56

intubation and mechanical ventilation

Question 57

treatment of myxedema coma

Answer 57

IV T4 300-500 mcg, then 75-100 mc daily, switch to PO

Question 58

supportive treatment of myxedema coma

Answer 58

IV steroids and fluids

Question 59

with treatment of myxedema coma

Answer 59

improvements in consciousness/TSH/vital signs are expected within 24 hours