Thyroid Disorders Flashcards
CM is a 65 y/o male with a hx of hypothyroidism. He’s admitted to the hospital and has an NPO order. He takes levothyroxine 100 mcg PO daily at home, and the provider would like to switch him to IV levothyroxine. What is the most appropriate dose of IV levothyroxine for the pharmacist to dispense?
a. 112 mcg
b. 50 mcg
c. 200 mcg
d. 100 mg
e. 75 mcg
e
The recommended IV to PO levothyroxine ratio is 0.75:1
AA is a 33 y/o female who’s been diagnosed with hyperthyroidism. She’s waiting for an appointment to see an endocrinologist. In the meantime, she has been given an Rx for propranolol. This med will:
a. Inhibit thyroid gland secretion of T3 and T4
b. Help control symptoms of hyperthyroidism
c. Inhibit thyroid gland synthesis of T3 and T4
d. Prevent the thyroid gland from absorbing iodine
e. Increase the peripheral conversion of T3 to T4
b
Beta blockers can help control symptoms of tachycardia and tremor associated with hyperthyroidism.
What is the most common cause of hypothyroidism?
a. Pregnancy
b. Iodine excess
c. Hashimoto’s disease
d. Graves’ disease
e. Radiation therapy
c
Hashimoto’s disease is an autoimmune disease in which a pt’s own antibodies attack the thyroid gland.
CC: “I have no energy.”
HPI: KB is a 32 y/o female who comes to the outpatient clinic on March 10th complaining of low energy, recent weight gain of 15 lbs, foggy memory, and feeling cold even though it’s sunny outside.
PMH: Allergic rhinitis, GERD
Current Meds: Cetirizine 10 mg PRN, Mylanta 20 mL Q6H, Tylenol 325 mg Q4-6H PRN, omega-3 fatty acid 1 g daily, MVI daily
Plan: Start levothyroxine 75 mcg daily. Follow-up on 4/14.
When should KB be instructed to take her levothyroxine?
a. With breakfast
b. An hour after breakfast
c. An hour before breakfast
d. With dinner
e. At bedtime with a light snack
c
Best taken in the morning on an empty stomach (water only), at least 60 min before breakfast.
CC: “I have no energy.”
HPI: KB is a 32 y/o female who comes to the outpatient clinic on March 10th complaining of low energy, recent weight gain of 15 lbs, foggy memory, and feeling cold even though it’s sunny outside.
PMH: Allergic rhinitis, GERD
Current Meds: Cetirizine 10 mg PRN, Mylanta 20 mL Q6H, Tylenol 325 mg Q4-6H PRN, omega-3 fatty acid 1 g daily, MVI daily
3/10 Labs:
TSH = 32 (0.3-3)
Free T4 = 0.3 (0.9-2.3)
Plan: Start levothyroxine 75 mcg daily. Follow-up on 4/14.
4/14 Labs:
TSH = 4.7 (0.3-3)
After the visit on 4/14, it would be appropriate to schedule KB to have her TSH level checked on:
a. April 21st
b. May 20th
c. July 14th
d. September 20th
e. October 14th
b
The TSH level should be monitored every 4-6 weeks until it’s within normal range and clinical symptoms have resolved.
CC: “I have no energy.”
HPI: KB is a 32 y/o female who comes to the outpatient clinic on March 10th complaining of low energy, recent weight gain of 15 lbs, foggy memory, and feeling cold even though it’s sunny outside.
PMH: Allergic rhinitis, GERD
Current Meds: Cetirizine 10 mg PRN, Mylanta 20 mL Q6H, Tylenol 325 mg Q4-6H PRN, omega-3 fatty acid 1 g daily, MVI daily
Vitals:
Height 5’7”, weight 138 lbs
3/10 Labs:
TSH = 32 (0.3-3)
Free T4 = 0.3 (0.9-2.3)
Plan: Start levothyroxine 75 mcg daily. Follow-up on 4/14.
4/14 Labs:
TSH = 4.7 (0.3-3)
In order to provide a full replacement dose of levothyroxine, KB’s initial daily dose prescribed on March 10th should have been:
a. 50 mcg
b. 75 mcg
c. 100 mcg
d. 112 mcg daily
e. 125 mcg daily
c
KB is a healthy adult and should start with a full replacement dose of levothyroxine per IBW (61.6 kg). A full replacement dose is 1.6 mcg/kg/day x 61.6 kg = 98.56 mcg.
CC: “I have no energy.”
HPI: KB is a 32 y/o female who comes to the outpatient clinic on March 10th complaining of low energy, recent weight gain of 15 lbs, foggy memory, and feeling cold even though it’s sunny outside.
PMH: Allergic rhinitis, GERD
Current Meds: Cetirizine 10 mg PRN, Mylanta 20 mL Q6H, Tylenol 325 mg Q4-6H PRN, omega-3 fatty acid 1 g daily, MVI daily
Vitals:
Height 5’7”, weight 138 lbs
3/10 Labs:
TSH = 32 (0.3-3)
Free T4 = 0.3 (0.9-2.3)
Plan: Start levothyroxine 75 mcg daily. Follow-up on 4/14.
4/14 Labs:
TSH = 4.7 (0.3-3)
Which drugs on KB’s med profile have an interaction with levothyroxine?
a. Mylanta and Tylenol
b. Cetirizine and MVI
c. Omega-3 fatty acid and cetirizine
d. MVI and Mylanta
e. Mylanta and omega-3 fatty acid
d
-Mylanta is an antacid that contains polyvalent cations (e.g., calcium, aluminum, magnesium).
-Antacids and multivitamins (containing ADEK, folate, iron) can decrease the absorption of levothyroxine.
-Doses of these meds should be separated from levothyroxine.
CC: “I have no energy.”
HPI: KB is a 32 y/o female who comes to the outpatient clinic on March 10th complaining of low energy, recent weight gain of 15 lbs, foggy memory, and feeling cold even though it’s sunny outside.
PMH: Allergic rhinitis, GERD
Current Meds: Cetirizine 10 mg PRN, Mylanta 20 mL Q6H, Tylenol 325 mg Q4-6H PRN, omega-3 fatty acid 1 g daily, MVI daily
Vitals:
Height 5’7”, weight 138 lbs
3/10 Labs:
TSH = 32 (0.3-3)
Free T4 = 0.3 (0.9-2.3)
Plan: Start levothyroxine 75 mcg daily. Follow-up on 4/14.
4/14 Labs:
TSH = 4.7 (0.3-3)
hCG = pos
On KB’s 4/14 visit, what changes should be made to her drug regimen?
a. The levothyroxine dose should be increased.
b. The levothyroxine dose should be decreased.
c. Levothyroxine should be changed to Armour Thyroid.
d. Levothyroxine should be discontinued.
e. Levothyroxine should be continued at the current dose.
a
KB’s serum TSH is not yet in the reference range. KB also has a positive pregnancy test on this visit. Levothyroxine is safe to use in pregnancy but typically higher (30-50%) doses are required.
A common side effect of propylthiouracil is:
a. Vision changes
b. Gastrointestinal upset
c. Hypotension
d. Thrombosis
e. Hyperglycemia
b
Both methimazole and PTU can cause GI side effects (N/V).
A medical resident asks the pharmacist for info on “desiccated thyroid” as he has heard that it’s a more naturally-derived product than other tx options. The pharmacist can tell him that desiccated thyroid:
a. Contains triiodothyronine (T3) only
b. Is the active ingredient in Armour Thyroid
c. Contains triiodothyronine (T3) and thyroxine (T4)
d. Is the same thing as propylthiouracil
e. Contains thyroxine (T4) only
b, c
What would be the expected levels of thyroid-stimulating hormone (TSH) and thyroid hormone (T4 and T3) in a pt with an underactive thyroid gland?
a. Low TSH, high T4
b. High TSH, high T3
c. High TSH, low T4
d. Low TSH, low T4
e. Low TSH, high T3
c
In hypothyroidism, T4 will be low, which signals the pituitary gland to increase the secretion of TSH.
Select the statement that correctly describes normal regulation of thyroid function.
a. TSH stimulates thyroid gland secretion of T4.
b. The pituitary gland produces the majority of T3.
c. T3 is converted to T4 in the periphery.
d. TSH levels are increased by elevations of T4.
e. T4 is more potent than T3.
a
What is the most common cause of hyperthyroidism?
a. Lithium
b. Iodine deficiency
c. Hashimoto’s disease
d. Graves’ disease
e. Tyrosine kinase inhibitors
d
Graves’ disease tends to occur in females in their 30s and 40s. It’s an autoimmune disorder where antibodies stimulate the thyroid to produce too much T4.
A pt has been taking Synthroid for many years. She inquires about using a generic product instead. Which reference should the pharmacist use to determine an appropriate generic substitution?
a. The Red Book
b. Clinical Pharmacology
c. The Orange Book
d. The Sanford Guide
e. Hansten and Horn’s
c
Which statement concerning the tx of hyperthyroidism during pregnancy is correct?
a. Methimazole is preferred in all trimesters.
b. Potassium iodide is preferred in the 3rd trimester.
c. All available treatments should be avoided d/t associated risks.
d. The tx of choice is radioactive iodine.
e. Propylthiouracil is preferred in the 1st trimester.
e
-PTU is used in the 1st trimester because of the fetal risk associated with methimazole.
-Methimazole can be used in the 2nd and 3rd trimesters.
