Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PharmD > Thyroid > Flashcards

Thyroid Flashcards

1
Q

What are the two types of thyroid disorders?

A

Hypothyroidism and hyperthyroidism

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

Does thyroid disease affect women or men more frequently?

A

Women

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

What are causes for hypothyroidism?

A
  1. Autoimmune thyroid disease
    - Hashimoto thyroiditis (most common in NA)
  2. Iatrogenic
    - surgical removal of thyroid
    - radioactive iodine therapy
    - amiodarone
    - lithium
    - sulfonylureas
    - immunotherapy
  3. Iodine deficiency (rare in NA)
  4. Resistance to thyroid hormone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a very sensitive indicator of hypothyroidism?

A

Elevated thyroid-stimulating hormone (TSH)

*Note: may be low or normal in pituitary or hypothalamic disease

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

What is subclinical hypothyroidism?

A

Elevated TSH but normal thyroid hormone levels

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

What are normal TSH levels?

A

0.3-0.4 mU/L

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

Should we treat subclinical hypothyroidism?

A

Can consider in following:
- TSH>10
- Abnormal lipid profile
- Symptoms of hypothyroidism
- Planning pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are some common or serious signs and symptoms of hypothyroidism?

A

Fatigue
Impaired memory
Constipation
Cold intolerance
Changes in skin or hair (coarse/dry)
Hypertension
Bradycardia

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

If TSH is abnormal or unclear, what else can we test?

A

fT4 (free thyroxine)
fT3 (free triiodothyronine)

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

What supplement can interfere with thyroid tests?

A

Biotin (discontinue for at least 48 hours prior to testing)

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

When are anti-TPO antibodies tested?

A

Helps indicate whether the disease is autoimmune in nature

Only tested if it helps with patient-management decisions (Ex: recurrent spontaneous abortion or miscarriages)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is secondary hypothyroidism?

A

Pituitary hypothyroidism
- TSH low or normal (fT4 usually low)

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

What is tertiary hypothyroidism?

A

Hypothalamic disorder
- TSH low or normal (fT4 usually low)

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

What’s a common cause of transiently elevated TSH? (typically not a cause for concern)

A

Recovering phase of nonthyroidal illness (cold)

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

What are TSH, fT3, and fT4 levels like when patients are resistant to thyroid hormone?

A

High TSH, fT3, and fT4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What’s the treatment of choice for hypothyroidism?

A

Levothyroxine (L-T4)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What the typical dosing for levothyroxine?

A

Adults= 1.6mcg/kg/day
Newborn= 10-15 mcg/kg/day

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

How often do we dose adjust?
Why do we pick this interval?

A

Every 6 weeks as needed
Time to new steady state after dose adjustment

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

How often do we dose adjust for pregnancy?

A

Every 4 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What’s the special dosing regimen for older patients?
Why?

A

Start with low dose of 12.5mcg/day

Titrate every 4 weeks

High doses and low TSH is associated with increased risk of fracture.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Why is replacing T4 preferred over replacing T3?

A

Not as stable as T4 (which has longer half-life).

Even long-acting T3 formulations resulted in fluctuations (too high)

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

Why is elevated T3 levels dangerous?

A

Increases risk of side effects like atrial fibrillation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Using T3 therapy in hypothyroidism is rare, but what is one situation where it can be helpful?

A

Short-term management for patient with thyroid cancer undergoing withdrawal of L-T4 when recombinant TSH is not an option for radioactive iodine therapy

It’s short half life makes it ideal for this use

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

Is a combo of L-T4 and T3 used often?

A

No. Little or no benefit shown

Rare scenario: if symptoms not relieved with L-T4 despite normal TSH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is desiccated thyroid? Is is used often?

A

Thyroid replacement therapy from animal thyroid.
No. Unreliable dosing. No clear therapeutic advantage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the risks of hypothyroidism and pregnancy?

A

Infertility and miscarriage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What happens to TSH levels in the first trimester? Why?

A

Usually low due to high beta hCG levels.

If not on the lower side or not suppressed, may indicate diagnosis of hypothyroidism.

Repeat TSH and begin treatment if TSH >4mU/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Is levothyroxine (L-T4) safe in pregnancy?

A

Yes. Vital for healthy fetal development

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Is T3 appropriate during pregnancy?

A

Not as sole therapy, as it does not cross the placenta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What dose adjustment is needed for pregnant patients who are already on L-T4?

A

Increase dose by 2 extra tablets per week immediately following a positive pregnancy test

Further adjust based on TSH levels (maintain between 03-2.5 mU/L)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Why is this dose adjustment needed during pregnancy?

A

Thyroid binding globulins increase during pregnancy so L-T4 requirements may increase up to 50%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

How often should you test TSH levels when pregnant?

A

Every 6 weeks or 4 weeks after dosage adjustment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

If pregnant patient is not on L-T4 therapy, what’s the ranging values?

A

TSH should be <4 mU/L
Initiate therapy if TSH>10 mU/L or if patient confirmed TSH>4 mU/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What’s a common drug interaction for pregnant patients?

A

Iron can decrease absorption of L-T4. Separate administration time by at least 6 hours.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Is levothyroxine safe during breastfeeding?

A

Yes

36
Q

What medical emergency can be caused by severe hypothyroidism?

A

Myxedema coma
- hypotension
- decreased level of consciousness

37
Q

How do you treat myxedema coma?

A

Levothyroxine 300-500mcg IV initially, followed by 100mcg IV daily
Concomitant hydrocortisone 100mg q8h IV

38
Q

What is thyrotoxicosis?

A

Excessive thyroid hormone

39
Q

What is subclinical hyperthyroidism? Is it common?

A

TSH levels are suppressed (lower than normal), but thyroid levels are normal

Yes, can be a risk factor for a.fib

40
Q

What is hyperthyroidism a risk factor for?

A

Atrial fibrillation

41
Q

When is treatment indicated for subclinical hyperthyroidism?

A

If patient is:
- older or frail.
- has risk factors for a.fib
- osteoporosis
- symptoms of thyroid hormone excess

42
Q

What are some causes of thyroid storm?

A
  • Radioactive iodine
  • Infection
  • Trauma
  • Surgery
  • Withdrawal from antithyroid drugs
43
Q

What are symptoms of hyperthyroidism?

A

Weight loss
Palpitations
Diarrhea
Heat intolerance
Anxiety
Eyelid lag/stare
Goitre/nodules

44
Q

How is hyperthyroidism diagnosed?

A
  1. TSH, fT3, fT4
  2. Thyroid scan
  3. Radioactive iodine uptake (RAIU)
45
Q

Which of the above test is contraindicated in pregnancy and breastfeeding?

A

Thyroid scan
Radioactive iodine uptake

46
Q

When is RAIU high or low in hyperthyroidism?

A

If the cause of hyperthyoidism is due to overactive thyroid, then the RAIU will be high.
Ex: Grave’s disease, goitre

If it’s due to external causes, then RAIU will be low.
Ex: thyroiditis, iatrogenic (due to meds)

47
Q

Which common drug or comorbid condition can suppress TSH?

A

Corticosteroids and depression

48
Q

When is thyroid surgery considered in hyperthyroidism?

A

Thyroid nodules
Large goitre
Grave’s disease (if likely to be pregnant)

49
Q

If patient is going the surgery route, how do medications come into play?

A

Antithyroid drugs to bring patient to euthyroid

50
Q

What is a common side effect to surgery?

A

Hypothyroidism
Monitor patient post-op to see when thyroid replacement is needed.

51
Q

Which condition do we need to be extra careful about hypothyroidism post-op? Why?

A

Graves orbitopathy
Fluctuating levels of thyroid can worsen the eye disease

52
Q

What are the pharmacological choices for hyperthyroidism?

A
  1. Radioactive iodine
  2. Methimazole and propylthiouracil
  3. Beta-blockers
  4. Iodine
  5. Corticosteroids
  6. Selenium
53
Q

How does radioactive iodine work? What’s the main side effect?

A

Ablate thyroid tissue

Hypothyroidism

54
Q

When is radioactive iodine contraindicated?

A

Pregnancy
Patient with significant orbitopathy (if used, use with corticosteroid under guidance of ophthalmologist)

55
Q

What are two anti-thyroid agents?

A

Methimazole and propylthiouracil

56
Q

How does methimazole and propylthiouracil work?

A

Decrease the production of thyroid hormone

At high doses, propylthiouracil can also block conversion of L-T4 to T3

57
Q

When should PTU and methimazole be stopped?

A

Prior to thyroid scan (5 days prior)

58
Q

How do you choose between methimazole and propylthiouracil?

A

Methimazole is preferred due to lower incidence of serious hepatotoxicity.

PTU should be avoided in children.

PTU can make thyroid more resistant to 131I.

Long term treatment of methimazole is more acceptable.

59
Q

What are side effects of antithyroid agents?

A

Allergy, rash, agranulocytosis, hepatotoxicity, nephrotoxicity

60
Q

Where does beta blockers come into hyperthyroidism therapy?

A

Adjunct in Grave’s disease and toxic nodules

61
Q

How does beta blockers help with hyperthyroidism?

A

Blocks the conversion of L-T4 to T3.

62
Q

When should we use beta blockers with caution?

A

Asthma, heart failure, obstructive respiratory disorders, Raynaud phenomenon

63
Q

Where does iodine come into hyperthyroidism?

A

It blocks thyroid hormone production and is given 1 hour after administration of antithyroid drug

64
Q

Where does corticosteroid therapy come into play?

A

In treatment-resistant cases to lower the level of fT3.

65
Q

When does selenium come into play?

A

Prevent worsening of mild Graves orbitopathy

66
Q

What is the typical dosing for selenium?

A

Selenium 100 mcg BID

67
Q

What is thyroid storm?

A

Life-threatening medical emergency due to severe thyrotoxicosis.

68
Q

How do you manage thyroid storm?

A

Aggressive treatment with antithyroid medication + beta blockers + corticosteroid

69
Q

Which beta blocker is preferred in thyroid storm?

A

Propranolol

70
Q

For patients with hyperthermia during thyroid storm, which agent should be used?

A

Tylenol.

Avoid ASA and NSAIDs, as they can displace protein bound thyroid hormone and increase circulating

71
Q

What’s the most common type of hyperthyroidism in pregnancy?

A

Grave’s disease

72
Q

What’s the projection of hyperthyroidism in pregnancy?

A

In most patients, it gets better in second and third trimester (so treatment may not be required).

May flare up again postpartum however.

73
Q

How do you manage hyperthyroidism in pregnancy?
Why is it important to treat

A

Treat to upper limits of normal for fT3 and fT4.
Should achieve good control prior to conception if possible (if unable, use lowest effective dose with antithyroid drugs)
If patient received radioactive iodine, wait at least 6 months before conceiving

If only low doses of antithyroid drugs are needed, a trial without treatment is ok.
Can try beta blocker for mild symptoms.

Hyperthyroidism can increase risk of fetal loss.

74
Q

If an anti-thyroid agent is needed during pregnancy, which agent is preferred?

A

Propylthiouracil preferred in first trimester due to lower risk of congenital abnormalities. Switch patient to PTU if ok.

Switch back to methimazole after first trimester to minimize risk of hepatoxicity

75
Q

For patient who are on existing hyperthyroidism treatment, how do you manage for pregnancy?

A

Aim for upper limit of normal to avoid overtreatment.

May need to decrease dose, as patient often go into remission.

76
Q

While pregnant patient are on antithyroid medications, what should they monitor?

A

Pre-treatment CBC and hepatic function tests that include ALT and bilirubin are recommended.

Neutropenia (most common in first 90 days)
Hepatic effects (within first 120 days)

Stop drug if they notice fever, rash, or jaundice

77
Q

How often should levels be checked in pregnancy?

A

Every 6-8 weeks

78
Q

How do you manage hyperthyroidism in breastfeeding?

A

Treat to upper limits of normal for fT3 and fT4 to avoid overtreating.
Avoid use of radioactive scans or iodine treatment.

Can use beta blocker short-term until control is achieved with antithyroid drugs.

79
Q

Which antithyroid drugs is preferred in breastfeeding?

A

Methimazole

80
Q

While pregnant patient are on antithyroid medications, what should they monitor?

A

Pre-treatment CBC, ALT, and bilirubin should be tested if possible.

Stop meds if patient has fever, rash, or jaundice.

Routine screening for s/e of drugs is not recommended.

81
Q

If patient presents with goitres, what are the two treatment options?

A

If euthyroid and growing to cause compressive symptoms= surgery
If higher TSH= levothyroxine

82
Q

What are risks associated with surgery?

A

Hypothyroidism, vocal cord paralysis

82
Q

What is the difference between thyroid nodule and goitre?

A

A goiter is an enlarged thyroid gland, while a nodule is a lump or enlarged area within the thyroid gland.

Nodules are common, but should be investigated to exclude malignancy.

82
Q

How do you determine if nodule is at risk of malignancy? If suspected, what’s the next step?

A

Thyroid imaging reporting and data system (TI-RADS) is a points-based system to determine risk.

If suspected, fine needle biopsy is performed

83
Q

What are risk factors that increase risk for malignacy?

A

<20 or >60 years of age
Family history
Lymphadenopathy (swollen lymph nodes)
Male
Nodule >4cm or rapidly growing
Nodule fixed to soft tissue
Previous malignancy
Prior radiation exposure
Vocal cord paralysis

84
Q

How do you treat toxic multinodular goitre or a hot nodule?

A

Radioactive iodine

PharmD (11 decks)

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