Chapter 31: Thyroid and Antithyroid Drugs Lilley: Pharmacology and the
Nursing Process, 10th Edition
1. A patient who is taking propylthiouracil for hyperthyroidism wants to know how
this medicine works. Which explanation by the nurse is accurate?
A. It promotes the formation of thyroid hormone.
B. It slows down the formation of thyroid hormone.
C. It destroys overactive cells in the thyroid gland.
D. It inactivates already existing thyroid hormone in the bloodstream.
Answer: B
Explanation: Propylthiouracil inhibits the enzyme thyroid peroxidase, which is necessary for
the synthesis of thyroid hormones (T3 and T4). It does not affect already circulating
hormone.
2. A patient, newly diagnosed with hypothyroidism, has received a prescription for
thyroid replacement therapy. The nurse will instruct the patient to take this
medication at which time of day?
A. In the morning
B. With the noon meal
C. With the evening meal
D. At bedtime
Answer: A
Explanation: Taking levothyroxine in the morning on an empty stomach minimizes food
interactions and mimics the body's natural circadian rhythm of thyroid hormone release,
reducing the risk of insomnia.
3. A patient has a diagnosis of primary hypothyroidism. Which statement
accurately describes this problem?
A. The hypothalamus is not secreting thyrotropin-releasing hormone (TRH);
therefore, thyroid-stimulating hormone (TSH) is not released from the pituitary gland.
B. The pituitary gland is dysfunctional and is not secreting TSH.
C. The abnormality is in the thyroid gland itself.
D. The abnormality is caused by an insufficient intake of iodine.
Answer: C
Explanation: Primary hypothyroidism originates from a dysfunction within the thyroid gland
itself, leading to an inability to produce sufficient thyroid hormones despite normal or
elevated TSH levels.
, 4. A patient with hypothyroidism is given a prescription for levothyroxine. When
the nurse explains that this is a synthetic form of the thyroid hormone, he states
that he prefers to receive more –natural forms of drugs. What will the nurse
explain to him about the advantages of levothyroxine?
A. It has a stronger effect than the natural forms.
B. Levothyroxine is less expensive than the natural forms.
C. The synthetic form has fewer adverse effects on the gastrointestinal tract.
D. The half-life of levothyroxine is long enough to permit once-daily dosing.
Answer: D
Explanation: Levothyroxine has a long half-life (about 7 days), allowing for consistent
hormone levels with once-daily dosing, which improves adherence and maintains stable
therapeutic effects.
5. When reviewing the laboratory values of a patient who is taking antithyroid
drugs, the nurse will monitor for which adverse effect?
A. Decreased glucose levels
B. Decreased white blood cell count
C. Increased red blood cell count
D. Increased platelet count
Answer: B
Explanation: Antithyroid drugs like propylthiouracil and methimazole can cause
agranulocytosis, a serious adverse effect characterized by a dangerously low white blood cell
count, increasing infection risk.
6. A 19-year-old student was diagnosed with hypothyroidism and has started
thyroid replacement therapy with levothyroxine. After 1 week, she called the
clinic to report that she does not feel better. Which response from the nurse is
correct?
A. -It will probably require surgery for a cure to happen.‖
B. -The full therapeutic effects may not occur for several weeks.‖
C. -Is it possible that you did not take your medication as instructed?‖
D. -Let’s review your diet; it may be causing absorption problems.‖
Answer: B
Explanation: Levothyroxine has a slow onset of action. It may take several weeks for patients
to experience the full therapeutic benefits and symptom relief due to the drug's long half-life
and the body's need to adjust.
, 7. A patient, newly diagnosed with hypothyroidism, receives a prescription for a
thyroid hormone replacement drug. The nurse assesses for which potential
contraindication to this drug?
A. Infection
B. Diabetes mellitus
C. Liver disease
D. Recent myocardial infarction
Answer: D
Explanation: Thyroid hormone replacement increases metabolic rate and cardiac workload,
which can be dangerous following a recent myocardial infarction. This is a key
contraindication.
8. During a teaching session for a patient on antithyroid drugs, the nurse will
discuss which dietary instructions?
A. Using iodized salt when cooking
B. Avoiding foods containing iodine
C. Restricting fluid intake to 2500 mL/day
D. Increasing intake of sodium- and potassium-containing foods
Answer: B
Explanation: Iodine is a substrate for thyroid hormone synthesis. Patients on antithyroid
drugs should avoid iodine-rich foods (e.g., seafood, iodized salt) to prevent counteracting the
drug's effect.
9. A 19-year-old woman has been diagnosed with hypothyroidism and has started
thyroid replacement therapy with levothyroxine. After 6 months, she calls the
nurse to say that she feels better and wants to stop the medication. Which
response by the nurse is correct?
A. –You can stop the medication if your symptoms have improved.I
B. –You need to stay on the medication for at least 1 year before a decision about
stopping it can be made.I
C. –You need to stay on this medication until you become pregnant.I
D. –Medication therapy for hypothyroidism is usually lifelong, and you should not
stop taking the medication.I
Answer: D
Explanation: Hypothyroidism is typically a permanent condition requiring lifelong hormone
replacement therapy. Abruptly stopping levothyroxine will lead to the return of hypothyroid
symptoms.
Nursing Process, 10th Edition
1. A patient who is taking propylthiouracil for hyperthyroidism wants to know how
this medicine works. Which explanation by the nurse is accurate?
A. It promotes the formation of thyroid hormone.
B. It slows down the formation of thyroid hormone.
C. It destroys overactive cells in the thyroid gland.
D. It inactivates already existing thyroid hormone in the bloodstream.
Answer: B
Explanation: Propylthiouracil inhibits the enzyme thyroid peroxidase, which is necessary for
the synthesis of thyroid hormones (T3 and T4). It does not affect already circulating
hormone.
2. A patient, newly diagnosed with hypothyroidism, has received a prescription for
thyroid replacement therapy. The nurse will instruct the patient to take this
medication at which time of day?
A. In the morning
B. With the noon meal
C. With the evening meal
D. At bedtime
Answer: A
Explanation: Taking levothyroxine in the morning on an empty stomach minimizes food
interactions and mimics the body's natural circadian rhythm of thyroid hormone release,
reducing the risk of insomnia.
3. A patient has a diagnosis of primary hypothyroidism. Which statement
accurately describes this problem?
A. The hypothalamus is not secreting thyrotropin-releasing hormone (TRH);
therefore, thyroid-stimulating hormone (TSH) is not released from the pituitary gland.
B. The pituitary gland is dysfunctional and is not secreting TSH.
C. The abnormality is in the thyroid gland itself.
D. The abnormality is caused by an insufficient intake of iodine.
Answer: C
Explanation: Primary hypothyroidism originates from a dysfunction within the thyroid gland
itself, leading to an inability to produce sufficient thyroid hormones despite normal or
elevated TSH levels.
, 4. A patient with hypothyroidism is given a prescription for levothyroxine. When
the nurse explains that this is a synthetic form of the thyroid hormone, he states
that he prefers to receive more –natural forms of drugs. What will the nurse
explain to him about the advantages of levothyroxine?
A. It has a stronger effect than the natural forms.
B. Levothyroxine is less expensive than the natural forms.
C. The synthetic form has fewer adverse effects on the gastrointestinal tract.
D. The half-life of levothyroxine is long enough to permit once-daily dosing.
Answer: D
Explanation: Levothyroxine has a long half-life (about 7 days), allowing for consistent
hormone levels with once-daily dosing, which improves adherence and maintains stable
therapeutic effects.
5. When reviewing the laboratory values of a patient who is taking antithyroid
drugs, the nurse will monitor for which adverse effect?
A. Decreased glucose levels
B. Decreased white blood cell count
C. Increased red blood cell count
D. Increased platelet count
Answer: B
Explanation: Antithyroid drugs like propylthiouracil and methimazole can cause
agranulocytosis, a serious adverse effect characterized by a dangerously low white blood cell
count, increasing infection risk.
6. A 19-year-old student was diagnosed with hypothyroidism and has started
thyroid replacement therapy with levothyroxine. After 1 week, she called the
clinic to report that she does not feel better. Which response from the nurse is
correct?
A. -It will probably require surgery for a cure to happen.‖
B. -The full therapeutic effects may not occur for several weeks.‖
C. -Is it possible that you did not take your medication as instructed?‖
D. -Let’s review your diet; it may be causing absorption problems.‖
Answer: B
Explanation: Levothyroxine has a slow onset of action. It may take several weeks for patients
to experience the full therapeutic benefits and symptom relief due to the drug's long half-life
and the body's need to adjust.
, 7. A patient, newly diagnosed with hypothyroidism, receives a prescription for a
thyroid hormone replacement drug. The nurse assesses for which potential
contraindication to this drug?
A. Infection
B. Diabetes mellitus
C. Liver disease
D. Recent myocardial infarction
Answer: D
Explanation: Thyroid hormone replacement increases metabolic rate and cardiac workload,
which can be dangerous following a recent myocardial infarction. This is a key
contraindication.
8. During a teaching session for a patient on antithyroid drugs, the nurse will
discuss which dietary instructions?
A. Using iodized salt when cooking
B. Avoiding foods containing iodine
C. Restricting fluid intake to 2500 mL/day
D. Increasing intake of sodium- and potassium-containing foods
Answer: B
Explanation: Iodine is a substrate for thyroid hormone synthesis. Patients on antithyroid
drugs should avoid iodine-rich foods (e.g., seafood, iodized salt) to prevent counteracting the
drug's effect.
9. A 19-year-old woman has been diagnosed with hypothyroidism and has started
thyroid replacement therapy with levothyroxine. After 6 months, she calls the
nurse to say that she feels better and wants to stop the medication. Which
response by the nurse is correct?
A. –You can stop the medication if your symptoms have improved.I
B. –You need to stay on the medication for at least 1 year before a decision about
stopping it can be made.I
C. –You need to stay on this medication until you become pregnant.I
D. –Medication therapy for hypothyroidism is usually lifelong, and you should not
stop taking the medication.I
Answer: D
Explanation: Hypothyroidism is typically a permanent condition requiring lifelong hormone
replacement therapy. Abruptly stopping levothyroxine will lead to the return of hypothyroid
symptoms.
