Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Summer Pharm Exam 1 > Thyroid > Flashcards

Thyroid Flashcards

(61 cards)

Start Studying
1
Q

What is your thyroid test of choice

A

TSH! thyroid stimulating hormone, released form anterior pituitary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is graves disease

A

AI d/o (Abs stimulate thyroid to make hormones) resulting in hyperthyroidism in early phase
can progress to hypothyroid later if there is gland destruction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a thyroid storm

A

severe thyrotoxicosis (excess thyroid hormone)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is goiter

A

enlargement of thyroid gland

can occur in hyper or hypothyroidism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the role of the thyroid

A

Normal growth and development in kids

metabolic stability in adults

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The first way the thyroid is regulated is

A

TSH secreted by anterior pituitary

Negative feedback on anterior pituitary is from circulating free thyroid hormone, and release of TRH from hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Extrathyroidal deiodination of T4 to T3 is regulated by

A 
nutrition 
nonthyroid hormones 
ambient temps 
drugs 
illness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How id thyroid hormone synthesized

A

Iodide transported from plasma to apical membrane of the cell, and coupled to TG
Hormone stored as colloid moves back towards basal membrane where T4 is secreted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where are the thyroid hormones formed and secreted

A

T4: secreted from thyroid ONLY
T3: 80% made from breakdown of T4 (5-monodeiodinase in extrathyroidal peripheral tissues converts T4 to T3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How are T4 and T3 transported in the bloodstream

A

They are bound to 3 proteins; thyroxine binding globulin, transthyretin, and albumin
99.6% are bound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are UNbound thyroid hormones able to do

A 
diffuse into cell 
elicit biologic effect 
regulate TSH (thyrotropin)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where are thyroid hormone receptors found

A

in hormone responsive tissues;
pituitary, liver, kidney, heart, skeletal muscle, lung, intestine
(T3 has more affinity for these receptors than T4)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does the body preserve homeostasis

A

by altering number of thyroid receptors

ex: starvation lowers T3 hormone and receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What thyroid hormone gives the negative feedback

A

T3!
When there is too much T3, it gives negative feedback to the thyroid to stop releasing TSH, and hypothalamus to stop releasing TRH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are S/Sx of thyrotoxicosis

A 
warm moist skin 
sweating 
tachycardia 
dyspnea 
tremor, weak
weight loss
menstrual irregularity 
graves: exophthalmos
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are S/Sx of hypothyroid

A 
pale, cool, puffy skin 
always cold 
bradycardia 
HTN 
PE
reduced appetite, weight gain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Many hypothyroid patients on treatment dont see weight loss, so what do they do

A

double the thyroid med dose causing heart and bone problems

advise patient that taking thyroid medication will NOT correct their weight gain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is Hashimotos

A

AI destruction of thyroid gland

early dz has goiter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What can cause hypothyroidism

A 
Hashimotos 
drug induced 
dyshormonegensis 
radiation 
congenital (cretinism) 
Seconadary (TSH deficiency)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What will primary hypothyroid labs show

A 
High TSH (>4.5) 
Decreased free T4
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What will secondary hypothyroid labs show

A

TSH within or below normal limits
Free/total T4 and T3 are low
antithyroid peroxidase Abs and anti-TG abs elevated if AI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What will subclinical hypothyroid labs show

A 
High TSH (>4.5) 
Normal free T4
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What lab do you not need to diagnose hypothyroidism

A

T3, free or total

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

When should subclinical hypothyroid be treated

A

Only if TSH >10, or if pt has iron deficiency anemia
-Controversial because some say there is no improvement with treatment, others say Tx can help improve lipid profiles and LV function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
How should you treat and monitor hypothyroidism in pregnant women
Adjust replacement therapy (increase dose from 25-50%) First trimester: monitor TSH monthly- goal is 2-2.5 second trimester: goal TSH <3 third trimester: goal TSH <3.5 postpartum: check TSH at 6 weeks
26
What labs shouldyou order for different thyroid disorders
Screening: TSH and fre T4 Hypo: TSH, anti-TG abs, anti-TPO abs Hyper: TSH, free T4, I uptake scan, anti-TPO and anti-TG abs Thyroid nodule: FNA, I uptake scan, Tc scan, US
27
Increased thyroid binding globulin will show what lab values
elevated total T4 and T3 | *free T4 and TSH will not be affected
28
What drugs can cause low serum T4 or T3
Naproxen Octreotide (somatostatin analog) Phenobarbitol Phenytoin
29
What drugs increase TSH (hypothyroid)
``` Phenytoin Amiodarone Dopamine antagonist salicylates naproxen estrogen or androgen excess ```
30
What disorders can alter lab results
``` severe illness pregnancy chronic protein malntr hepatic failure nephrotic syndrome ```
31
What is first line for treating hypothyroidism
``` Levothyroxine; synthetic T4 that is relatively inexpensive, chemically stable, with uniform potency dose daily (half life 7 days) WHITE TABLET is 50 mcg; relative dose is 100mcg so usually Rx 2 white pills ```
32
If you change a dose of levothyroxine, how long do you wait to recheck lab values
4-5 weeks; half life is 7 days, wait 4-5 half lives | apps. 6 weeks
33
How are T4 and TSH related
non-linearly | small changes in T4 can have enormous changes in TSH
34
How do you take levothyroxine
with water, on an empty stomach, 1 hr before breakfast food impairs it's absorption (as well as mucosal diseases- sprue, diabetic diarrhea, ileal bypass surgery) -give meds that interact with levothyroxine 4 hours after T4 dose
35
What can impair absorption of levothyroxine in the GI tract
*cholestyramine (bile acid resin) *calcium carbonate sucralfate aluminum hydroxide *ferrous sulfate dietary fiber espresso *histamine blockers, PPI
36
What drugs increase T4 clearance
Rifampin carbamazepine phenytoin *selenium deficiency and amiodarone block conversion of T4 to T3
37
What do some people say happens when they take T3 (Cytomel)
they get a burst of energy | but; some formulations deliver too much T3
38
What is Armour thyroid
Dessicated pork thyroid gland
39
Most patients require this dose once they reach steady state
1.7 mcg/kg/day levothyroxine | dose is based on ideal body weight, not actual body weight
40
How do you dose young patients w/ long standing dz or pt <45 w/o cardiac disease
Start on Levothyroxine 50mcg daily, increase to 100mcg daily after 1 month
41
Recommended dosing for older patients with CAD on levothyroxine
Start 25 mcg per day | titrate up 25mcg at monthly intervals
42
Why do pregnant women need a higher thyroxine dose
increased degredation by placental deiodinase increased T4 pool size transfer of T4 to fetus *also may need to increase dose in post-menopausal women*
43
What are some disease drug interactions in hypothyroidism
High serum digoxin values 2/2 decreased drug distribution | Decreased sensitivity to warfarin (low K clotting factors)-
44
Excess thyroid hormone can lead to
HF angina pectoris MI -hyperremodeling of cortical and trabecular bone= reduced bone density and increased risk of Fx
45
What is the least allergenic levothyroxine tables
``` 50mcg tab (WHITE) no dye, few excipients- try this in pts suspected of thyroid hormone allergy ```
46
What are symptoms of hyperparathyroid
``` nervous anxiety emotionally labile palpitations menstrual disturbance heat intolerance **Weight loss with increased appetite** ```
47
Hyperthyroid PE findings include
warm, smooth moist skin fine hair graves: exopthalmos and pretibial myxedema
48
How do you treat hyperthyroidism
anti-thyroid drugs (first line in kids, teen, and pregnant) RAI surgery
49
Advantages and disadvantages of anti-thyroid drugs are
Ad: non-invasive, low cost, low risk permanent hypothyroid Dis: low cure rate, drug interactions, hard to comply
50
What are the Thiourea (antithyroid) drugs
Propothyrouracil and Methimazole Preferential substrates to iodinating peroxidase= inhibited coupling of mono/diiodityrosine so T3 and T4 do not form Take 4-8 weeks to see normalization of thyroid hormone
51
What are the pharmacokinetics behind thiourea drugs
mostly absorbed in GI tract (peak concentration 1hr s/p eating) concentrated in thyroid gland excreted in urine
52
How are Thiourea drugs doses
PTU: 300-600 mg daily, TID/QID MMI: 30-60mg daily, BID/TID -can also give them as one dose change dose on a monthly basis (allow T4 to reach steady state)
53
ADE of thiourea drugs are
``` Pruritic maculopapular rash benign transient leukopenia agranulocytosis arthralgias Lupus like syndrome *hepatotoxicity ```
54
When is the only time PTU is considered a first line drug
First trimester pregnancy, at lowest possible dose to maintain maternal T4 in normal-high range WHY? because in first trimester, embryopathy associated w/ MMI is worse than hepatotoxicity associates with PTU
55
When on thiourea drugs while pregnant, your goal is to
prevent fetal goiter and suppress fetal thyroid function | *PTU <200= not likely to get fetal goiter
56
What is the MOA of Iodides
block thyroid hormone release inhibit thyroid hormone synthesis (interfere w/ intrathyroidal iodide utilization) decrease size and vascularity of thyroid gland *BUT- thyroid hormone synthesis still continues, so you get a thyroid full of stored hormones that cant release them
57
When should you give potassium iodide
7-14 days preoperatively | *If giving w/ RAI, give SSKI 3-7 days after Tx so radioactive iodide can concentrate in the thyroid
58
ADE of Iodides are
salivary gland swelling | iodism (metallic taste, burning mouth/throat, sore teeth and gums, gynecomastia)
59
Radioactive iodine is the best Tx for
toxic nodules toxic multinodular goiter *good cure rate of hyperthyroid
60
Disadvantages of RAI are
permanent hypothyroidism | Cant get pregnant for 6-12 months; can NOT breast feed
61
When s surgery used in hyperthyroidism
If pregnant and have major ADE from anti-thyroid drugs | if you have a coexisting susp nodule

Summer Pharm Exam 1 (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions