NCLEX-RN Endocrine Pharmacology Practice
Questions |
20 Original ATI & Next Gen NCLEX (NGN)
Case-Based MCQs with Detailed Rationales
Question 1
Clinical Scenario
A 42-year-old female client with a history of primary
hypothyroidism is admitted to the medical-surgical unit. She
has been taking levothyroxine 112 mcg PO daily for the past
three years. During the morning assessment, the nurse
notes that the client is alert and oriented but complains of
feeling cold, experiencing dry skin, and having persistent
constipation. Her vital signs are: temperature 97.4°F
(36.3°C), heart rate 54/min, respiratory rate 12/min, and
blood pressure 102/64 mmHg.
Question Stem
Which laboratory result should the nurse anticipate
reviewing to evaluate the therapeutic efficacy of the client's
current thyroid replacement therapy?
,A. Free triiodothyronine ($T_3$)
B. Total thyroxine ($T_4$)
C. Serum thyroid-stimulating hormone (TSH)
D. Serum thyroglobulin antibodies
Correct Answer
Correct Answer: C. Serum thyroid-stimulating hormone
(TSH)
Detailed Rationale
In primary hypothyroidism, the thyroid gland itself is
dysfunctional and cannot produce adequate thyroid
hormones. The pituitary gland compensates by secreting
elevated levels of thyroid-stimulating hormone (TSH) to
stimulate the thyroid. When a client receives therapeutic
doses of synthetic thyroid hormone (levothyroxine), the
negative feedback loop is restored, and pituitary secretion of
TSH decreases back into the normal reference range
(typically 0.5 to 5.0 mIU/L). Therefore, serum TSH is the most
sensitive and clinically reliable laboratory parameter used to
monitor the adequacy and therapeutic efficacy of
levothyroxine replacement therapy in primary
hypothyroidism.
The client's assessment findings (bradycardia, hypothermia,
constipation, cold intolerance, dry skin) strongly suggest
,that her current dose of levothyroxine is insufficient,
meaning her TSH is likely still elevated.
• Option A and B ($T_3$ and $T_4$) are not the primary
monitoring parameters for daily levothyroxine titration
because their serum levels can fluctuate and do not
reflect pituitary feedback homeostasis as sensitively as
TSH.
• Option D (thyroglobulin antibodies) is used to diagnose
autoimmune thyroiditis (Hashimoto's disease) but does
not measure the therapeutic efficacy or dosage
adequacy of levothyroxine therapy.
Learning Objectives
After completing this question, the learner should be able
to:
• Identify serum TSH as the primary laboratory standard
for monitoring levothyroxine therapy in primary
hypothyroidism.
• Recognize the clinical signs of under-replacement
(hypothyroidism) in a client taking levothyroxine.
• Explain the negative feedback loop governing the
pituitary-thyroid axis.
Medication Safety Focus
, Monitoring
Question 2
Clinical Scenario
A 28-year-old female client is diagnosed with Graves'
disease (hyperthyroidism) and is prescribed propylthiouracil
(PTU). She is currently at 10 weeks of gestation with her first
pregnancy.
Question Stem
Which clinical rationale explains why propylthiouracil (PTU)
is selected for this client instead of methimazole?
A. PTU does not cross the placental barrier and has no risk of
fetal harm.
B. Methimazole is associated with a high risk of maternal
hepatotoxicity in the first trimester.
C. PTU carries a lower risk of causing congenital
malformations during the first trimester.
D. PTU stimulates fetal thyroid hormone production to
prevent gestational hypothyroidism.
Correct Answer
Correct Answer: C. PTU carries a lower risk of causing
congenital malformations during the first trimester.
Questions |
20 Original ATI & Next Gen NCLEX (NGN)
Case-Based MCQs with Detailed Rationales
Question 1
Clinical Scenario
A 42-year-old female client with a history of primary
hypothyroidism is admitted to the medical-surgical unit. She
has been taking levothyroxine 112 mcg PO daily for the past
three years. During the morning assessment, the nurse
notes that the client is alert and oriented but complains of
feeling cold, experiencing dry skin, and having persistent
constipation. Her vital signs are: temperature 97.4°F
(36.3°C), heart rate 54/min, respiratory rate 12/min, and
blood pressure 102/64 mmHg.
Question Stem
Which laboratory result should the nurse anticipate
reviewing to evaluate the therapeutic efficacy of the client's
current thyroid replacement therapy?
,A. Free triiodothyronine ($T_3$)
B. Total thyroxine ($T_4$)
C. Serum thyroid-stimulating hormone (TSH)
D. Serum thyroglobulin antibodies
Correct Answer
Correct Answer: C. Serum thyroid-stimulating hormone
(TSH)
Detailed Rationale
In primary hypothyroidism, the thyroid gland itself is
dysfunctional and cannot produce adequate thyroid
hormones. The pituitary gland compensates by secreting
elevated levels of thyroid-stimulating hormone (TSH) to
stimulate the thyroid. When a client receives therapeutic
doses of synthetic thyroid hormone (levothyroxine), the
negative feedback loop is restored, and pituitary secretion of
TSH decreases back into the normal reference range
(typically 0.5 to 5.0 mIU/L). Therefore, serum TSH is the most
sensitive and clinically reliable laboratory parameter used to
monitor the adequacy and therapeutic efficacy of
levothyroxine replacement therapy in primary
hypothyroidism.
The client's assessment findings (bradycardia, hypothermia,
constipation, cold intolerance, dry skin) strongly suggest
,that her current dose of levothyroxine is insufficient,
meaning her TSH is likely still elevated.
• Option A and B ($T_3$ and $T_4$) are not the primary
monitoring parameters for daily levothyroxine titration
because their serum levels can fluctuate and do not
reflect pituitary feedback homeostasis as sensitively as
TSH.
• Option D (thyroglobulin antibodies) is used to diagnose
autoimmune thyroiditis (Hashimoto's disease) but does
not measure the therapeutic efficacy or dosage
adequacy of levothyroxine therapy.
Learning Objectives
After completing this question, the learner should be able
to:
• Identify serum TSH as the primary laboratory standard
for monitoring levothyroxine therapy in primary
hypothyroidism.
• Recognize the clinical signs of under-replacement
(hypothyroidism) in a client taking levothyroxine.
• Explain the negative feedback loop governing the
pituitary-thyroid axis.
Medication Safety Focus
, Monitoring
Question 2
Clinical Scenario
A 28-year-old female client is diagnosed with Graves'
disease (hyperthyroidism) and is prescribed propylthiouracil
(PTU). She is currently at 10 weeks of gestation with her first
pregnancy.
Question Stem
Which clinical rationale explains why propylthiouracil (PTU)
is selected for this client instead of methimazole?
A. PTU does not cross the placental barrier and has no risk of
fetal harm.
B. Methimazole is associated with a high risk of maternal
hepatotoxicity in the first trimester.
C. PTU carries a lower risk of causing congenital
malformations during the first trimester.
D. PTU stimulates fetal thyroid hormone production to
prevent gestational hypothyroidism.
Correct Answer
Correct Answer: C. PTU carries a lower risk of causing
congenital malformations during the first trimester.
