Thyroid

Question 1

1. The serum T4 level is not a good test for screening and monitoring for thyroid disease because:
   A. The assay is difficult to perform and not available in most clinical laboratories
   B. The results can be affected by alteration in protein binding, making interpretation difficult
   C. It is too sensitive, with a high percent of false positive results
   D. Serum T3 is a better test since it is the active hormone
   E. All of the above

Answer 1

B

Question 2

2. The prevalence of hypothyroidism is higher in:
   A. Women
   B. Elderly patients
   C. Patients with other autoimmune endocrine disorders
   D. Patients treated with amiodarone
   E. All of the above are correct

Answer 2

A

Question 2

3. What is the target TSH range (mIU/L or μIU/mL) for patients being treated for
   hypothyroidism or hyperthyroidism?
   A. Undetectable
   B. 2.5 to 4.5
   C. 1.4 to 2.5
   D. 0.5 to 4
   E. 4 to 5

Answer 2

D

Question 2

4. Which of the following is a reasonable choice in treating a patient with newly diagnosed hypothyroidism?
   A. Desiccated thyroid
   B. liotrix
   C. levothyroxine
   D. liothyronine
   E. All are reasonable choices

Answer 2

C

Question 3

5. Levothyroxine products should not be substituted at refill because:
   A. No marketed products are AB rated by the FDA Orange Book.
   B. All state regulations prohibit the substitution of narrow therapeutic index drugs.
   C. Small differences in bioavailability may result in loss of disease control.
   D. Patients will be nonadherent if it is switched.
   E. A and B are correct.

Answer 3

C

Question 4

6. Patients with mild or subclinical hypothyroidism should be considered for LT4 therapy if the patient has:
   A. A family history of thyroid disease
   B. Elevated LDL cholesterol
   C. Positive TSHR-AbS antibody
   D. A history of hypertension
   E. All of the above

Answer 4

B

Question 5

7. What is the starting daily dose of LT4 in an 87 kg (191 lb), 5’4” (163 cm) 32-year old patient, otherwise healthy, with overt hypothyroidism?
   A. 25 mcg
   B. 50 mcg
   C. 75 mcg
   D. 100 mcg
   E. 150 mcg

Answer 5

D

Question 6

8. In a patient receiving stable LT4 therapy, laboratory monitoring should be performed every
   A. Month
   B. 6 to 8 weeks
   C. 3 months
   D. Year
   E. 5 years

Answer 6

D

Question 7

9. Which of the following is a consequence of undertreatment with LT4?
   A. Hypercholesterolemia
   B. Cardiovascular disease
   C. Fatigue
   D. Infertility
   E. All of the above

Answer 7

E

Question 8

10. Untreated hyperthyroidism in the elderly can result in:
    A. Mania
    B. Atrial fibrillation
    C. Deafness
    D. Hirsutism
    E. A and D are true

Answer 8

B

Question 9

11. Which of the following drugs may be used to quickly relieve symptoms seen in
    hyperthyroidism?
    A. Radioactive iodine
    B. Propylthiouracil
    C. Methimazole
    D. Lithium
    E. Propranolol

Answer 9

E

Question 10

12. Why is propylthiouracil (PTU) the antithyroid therapy of choice in pregnant patients with Graves disease?
    A. It is less hepatotoxic than methimazole (MMI)
    B. It may be less teratogenic than MMI
    C. It has less risk of causing fetal hypothyroidism than MMI
    D. It causes less agranulocytosis in these patients than MMI
    E. A and C are true

Answer 10

B

Question 11

13. In the setting of antithyroid therapy, which of the following statements regarding agranulocytosis is not true?
    A. Agranulocytosis occurs in 0.3% of patients.
    B. Patients may present with fever and sore throat.
    C. Monitoring for agranulocytosis is controversial.
    D. Incidence of agranulocytosis is higher in patients treated with propylthiouracil.
    E. Agranulocytosis usually occurs within the first 3 months of therapy.

Answer 11

D

Question 12

14. Why has use of methimazole increased dramatically in the United States compared to propylthiouracil (PTU) in the treatment of most patients with Graves disease?
    A. It may cause fewer adverse effects such as hepatotoxicity than PTU.
    B. It has a shorter half-life than PTU.
    C. It is renally excreted so no adjustment is needed for liver disease.
    D. It blocks the conversion of T4 to T3.
    E. A and D are true

Answer 12

A

Question 13

15. Why should critically ill patients with nonthyroidal illness (“euthyroid sick syndrome”) and a low serum T4 level not be treated with LT4?
    A. The alteration in the thyroid axis is an appropriate physiologic response to metabolic stress.
    B. Liothyronine (T3) is the preferred treatment
    C. There is no intravenous form of LT4 to administer in the ICU.
    D. The low serum T4 improves patient outcomes.
    E. A and D are true

Answer 13

D

Question 14

A 36-year-old, 68-kg (150 lb) female presents to your pharmacy clinic complaining of 2 months of fatigue, menorrhagia, and occasional constipation. Her vital signs are normal, and she is otherwise healthy. Her only medications are a hormonal contraceptive, daily multivitamin product and prn Tums® (calcium carbonate) for heartburn.

1. The best test/approach for assessing this patient for hypothyroidism is:
   A. Measure serum T 3 and T 4 levels
   B. Measure serum TSH (thyrotropin) level and FT 4 (free thyroxine)
   C. An empiric trial of levothyroxine
   D. An empiric trial of levothyroxine and ferrous sulfate

Answer 14

B

Option B: Correct. TSH is the gold standard test for screening, diagnosing, and monitoring patients for both hypo- and hyperthyroidism. Since the patient is symptomatic, many clinicians
would also order a FT 4 to further confirm a diagnosis of hypothyroidism.

Question 15

A 36-year-old, 68-kg (150 lb) female presents to your pharmacy clinic complaining of 2 months of fatigue, menorrhagia, and occasional constipation. Her vital signs are normal, and she is otherwise healthy. Her only medications are a hormonal contraceptive, daily multivitamin product and prn Tums® (calcium carbonate) for heartburn.

2. If this patient has mild or subclinical hypothyroidism, which therapy has been shown in clinical trials to improve patient outcomes?
   A. Liothyronine (LT 3 )
   B. Levothyroxine (LT 4 )
   C. T 3 and T 4 combination therapy
   D. None of the above

Answer 15

2. Answer: D

Option D: Correct. There is no strong evidence that any thyroid replacement therapy improves quality of life or thyroid symptoms in patients with subclinical hypothyroidism.

Question 16

A 36-year-old, 68-kg (150 lb) female presents to your pharmacy clinic complaining of 2 months of fatigue, menorrhagia, and occasional constipation. Her vital signs are normal, and she is
otherwise healthy. Her only medications are a hormonal contraceptive, daily multivitamin product and prn Tums® (calcium carbonate) for heartburn.

3. What is the target TSH range for this patient’s therapy?
   A. Undetectable (<0.1 mIU/L [µIU/mL]
   B. 0.5 to 4.5 mIU/L [µIU/mL]
   C. 0.5 to 2.5 mIU/L [µIU/mL]
   D. Greater than 4.5 mIU/L [µIU/mL]

Answer 16

3. Answer: C

Option C: Correct. This is the range in which risks are minimized and benefits are maximized.

Question 17

A 36-year-old, 68-kg (150 lb) female presents to your pharmacy clinic complaining of 2 months of fatigue, menorrhagia, and occasional constipation. Her vital signs are normal, and she is otherwise healthy. Her only medications are a hormonal contraceptive, daily multivitamin product and prn Tums® (calcium carbonate) for heartburn.

4. If this patient has overt hypothyroidism, what would be the full LT 4 replacement dose?
   A. 50 mcg
   B. 75 mcg
   C. 100 mcg
   D. 137 mcg

Answer 17

4. Answer: C

Option C: Correct. This is the correct full replacement dose (rounded to common tablet size), 1.6
mcg/kg/day.

Question 18

A 36-year-old, 68-kg (150 lb) female presents to your pharmacy clinic complaining of 2 months of fatigue, menorrhagia, and occasional constipation. Her vital signs are normal, and she is
otherwise healthy. Her only medications are a hormonal contraceptive, daily multivitamin product and prn Tums® (calcium carbonate) for heartburn.

5. If the patient is receiving LT 4 replacement and is started on chronic proton pump inhibitor (PPI) therapy for gastroesophageal reflux disease, what potential impact might the PPI have on
   her therapy?
   A. Increased LT 4 dose requirement
   B. Decreased LT 4 dose requirement
   C. Increased risk of PPI adverse drug events
   D. Increased risk of failure of her hormonal contraceptive

Answer 18

5. Answer: A

Option A: Correct. Decreased gastric acid and elevated gastric pH may reduce the absorption of
LT 4 tablets.

Question 19

6. Levothyroxine products should not be substituted at refill because:

A. No marketed products are AB rated by the FDA Orange Book.
B. All state regulations prohibit the substitution of narrow therapeutic index (NTI) drugs.
C. Small differences in bioavailability may result in loss of disease control.
D. Brand name LT 4 products are inherently better than generics.

Answer 19

C

Question 20

7. A 32-year-old female with stable hypothyroidism, treated with LT 4 100 mcg/day, becomes pregnant. What change will most likely need to be made in her LT 4 therapy?

A. Reduce the dose to 50 mcg
B. No change in dose
C. Increase the dose to 125 mcg/day
D. Increase the dose to 200 mcg/day

Answer 20

C

Option C: Correct. Most patients will require a 20% to 30% increase in dose.

Question 21

8. After the above patient with hypothyroidism delivers her baby, what change will most likely need to be made to her LT 4 dose?

A. Maintain the dose she used while pregnant for at least 6 months
B. Return to her prepregnancy dose
C. Increase her dose by two tablets per week
D. Reduce the dose by 50%

Answer 21

8. Answer: B

Option B: Correct. Most patients can return to their prepregnancy dose immediately after delivery. Most patients require a 20% to 30% dose increase during pregnancy.

Question 22

9. Which anticancer agents are associated with a significant risk of causing thyroid dysfunction?

A. Anthracyclines such as doxorubicin
B. Antimetabolites such as methotrexate
C. Immune checkpoint inhibitors such as nivolumab
D. Angiogenesis inhibitors such as bevacizumab

Answer 22

C

Question 23

10. In what setting of antithyroid therapy would PTU be used preferentially over MMI? A. Patient with a history of MMI-associated agranulocytosis. B. Patient with adherence issues since PTU is given once daily. C. Patient with chronic kidney disease. D. Patient in the first trimester of pregnancy.

Answer 23

D

Question 24

11. Why should critically ill patients with nonthyroidal illness (“euthyroid sick syndrome”) and a low serum T 4 level not be treated with LT 4 ? A. The alteration in the thyroid axis is an appropriate physiologic response to metabolic stress. B. Levothyroxine (LT 4 ) will not effectively manage this syndrome. C. There is no intravenous (IV) form of LT 4 to administer in the ICU. D. The low serum T 4 improves patient outcomes.

Answer 24

A Option A: Correct. In severe illness, downregulation of the thyroid axis is thought to be an appropriate physiologic response. Option B: Incorrect. There is no evidence that LT 4 administration improves outcomes in patients who are not truly hypothyroid. Option C: Incorrect. An IV formulation of LT 4 is available. Option D: Incorrect. Low serum T 4 is a marker for worse outcomes in critically ill patients.

Question 25

The following case should be used to answer questions 12 and 13. An 82-year-old, 56-kg (123 lb) female is diagnosed with hypothyroidism. She has a history of hypertension and atrial fibrillation. Current medications include apixaban 2.5 mg bid, metoprolol tartrate 25 mg bid, lisinopril 20 mg qday, calcium carbonate 500 mg qday, Vitamin D3 5000 IU qday, and a multivitamin with iron qday. 12. Which of the following is an appropriate LT 4 starting dose for this patient? A. 25 mcg B. 50 mcg C. 75 mcg D. 100 mcg

Answer 25

A

Question 26

The following case should be used to answer questions 12 and 13. An 82-year-old, 56-kg (123 lb) female is diagnosed with hypothyroidism. She has a history of hypertension and atrial fibrillation. Current medications include apixaban 2.5 mg bid, metoprolol tartrate 25 mg bid, lisinopril 20 mg qday, calcium carbonate 500 mg qday, Vitamin D3 5000 IU qday, and a multivitamin with iron qday. 13. With her current medications, what is the best time for the patient to take her LT 4 ? A. 2 hours before breakfast B. In the morning with calcium and iron supplements C. At noon with lunch D. At bedtime

Answer 26

D Option D: Correct. Bioavailability may be best with bedtime administration.

Question 27

14. A 26-year-old female with anxiety, tremor, weight loss, and tachycardia is diagnosed with Graves’ disease. Which medication will provide the quickest improvement in her symptoms? A. PTU B. MMI C. Propranolol D. Lugol’s solution

Answer 27

C

Question 28

15. A 19-year-old female with tremor, weight loss, and tachycardia is diagnosed with Graves’ disease. Her TSH level is undetectable and free T 4 level is elevated. She is treated with MMI. One month later, she is complaining of fever and sore throat. Based on these symptoms, your immediate concern is MMI-associated _____________. A. Hepatitis B. Agranulocytosis C. ANCA-positive vasculitis D. Lupus

Answer 28

B