A client who takes levothyroxine also uses a high-dose biotin supplement for hair and nails. What should the nurse teach?
Tell the provider, because it can skew thyroid test results
✓
Take it with the levothyroxine to improve absorption
Stop the levothyroxine while using the supplement
Expect the supplement to raise the levothyroxine dose needed
Correct Answer
Tell the provider, because it can skew thyroid test results
Biotin can interfere with the immunoassays used to measure TSH, T4 and T3 and produce misleading thyroid results, so the client tells the provider about it, and it is usually stopped for a short time before thyroid blood tests. Taking it with the levothyroxine to improve absorption is wrong, because biotin does not improve absorption. Stopping the levothyroxine while using the supplement would leave hypothyroidism untreated. Expecting the supplement to raise the levothyroxine dose needed is wrong, because the problem lies with the test, not with how the drug works.
Category: Thyroid Replacement
Question 2
A client who takes levothyroxine is also prescribed ferrous sulfate. What should the nurse teach?
Take both drugs together with milk
Take the two drugs several hours apart
✓
Take both drugs at bedtime with a snack
Stop the levothyroxine while taking iron
Correct Answer
Take the two drugs several hours apart
Iron binds levothyroxine in the gut and reduces its absorption, and calcium supplements and calcium antacids do the same, so these products are separated from the thyroid dose by several hours. Taking both drugs together with milk adds calcium and worsens the binding. Taking both drugs at bedtime with a snack combines them and adds food. Stopping the levothyroxine is never the answer, because thyroid replacement continues without interruption.
Category: Thyroid Replacement
Question 3
The boxed warning for levothyroxine cautions against its use for which purpose?
Replacement after removal of the thyroid gland
Treatment of Hashimoto thyroiditis
Weight loss in people with normal thyroid function
✓
Treatment of congenital hypothyroidism
Correct Answer
Weight loss in people with normal thyroid function
Levothyroxine carries a boxed warning that it must not be used to treat obesity or for weight loss, because doses large enough to affect weight in a person with normal thyroid function can cause serious or life-threatening toxicity. Replacement after removal of the thyroid gland is a standard use. Treatment of Hashimoto thyroiditis, the autoimmune cause of hypothyroidism, is a standard use. Treatment of congenital hypothyroidism is also an approved use.
Category: Thyroid Replacement
Question 4
An older adult with coronary artery disease begins levothyroxine. Which new finding should the client report right away?
Warmer hands and feet
More regular bowel movements
A slight rise in energy
Chest pain
✓
Correct Answer
Chest pain
Thyroid hormone raises heart rate and myocardial oxygen demand, so older adults and clients with heart disease start at a low dose, and chest pain, palpitations or a new irregular rhythm are reported at once. Warmer hands and feet reflect a return toward a normal metabolic rate. More regular bowel movements are an expected improvement as constipation from hypothyroidism resolves. A slight rise in energy is an expected therapeutic response.
Category: Thyroid Replacement
Question 5
A client who takes warfarin is started on levothyroxine. Which laboratory value should the nurse expect to be monitored more closely?
INR, for an increased anticoagulant effect
✓
Serum potassium, for a falling level
Blood glucose, for a falling level
Platelet count, for a rising level
Correct Answer
INR, for an increased anticoagulant effect
Thyroid hormone speeds the breakdown of clotting factors, so correcting hypothyroidism increases the response to warfarin; the INR is followed and the warfarin dose may need to be lowered. Serum potassium is not expected to fall from this combination. Blood glucose tends to rise, not fall, when thyroid hormone is started in a client with diabetes. A rising platelet count is not an effect of this interaction.
Category: Thyroid Replacement
Question 6
Before levothyroxine is started, which coexisting condition must be corrected first?
Iron deficiency anemia
Adrenal insufficiency
✓
Mild hypertension
Vitamin D deficiency
Correct Answer
Adrenal insufficiency
Thyroid hormone raises the metabolic rate and the body's need for cortisol, so giving it to a client with uncorrected adrenal insufficiency can trigger an acute adrenal crisis; glucocorticoid replacement is started first. Iron deficiency anemia matters for timing of iron doses but does not have to be corrected before starting. Mild hypertension is monitored but is not a contraindication. Vitamin D deficiency is unrelated to the safety of starting thyroid hormone.
Category: Thyroid Replacement
Question 7
A client who takes methimazole reports a sore throat and fever. What should the nurse tell the client?
Take acetaminophen and keep taking the drug
Gargle with salt water and keep taking the drug
Report it promptly so blood counts can be checked
✓
Double the next dose to control symptoms
Correct Answer
Report it promptly so blood counts can be checked
Thionamides can cause agranulocytosis, a sudden loss of white blood cells, and sore throat with fever is often its first sign, so the client reports it at once and a white blood cell count with differential is checked before more doses are taken. Taking acetaminophen and continuing the drug could mask an infection that is becoming life-threatening. Gargling with salt water and continuing the drug delays needed evaluation. Doubling the next dose would increase exposure to the drug that may be causing the problem.
Category: Antithyroid Drugs
Question 8
Calcitonin can lower the blood level of which drug by increasing its excretion in the urine?
Digoxin
Warfarin
Phenytoin
Lithium
✓
Correct Answer
Lithium
Calcitonin increases urinary clearance of lithium, so a client taking both may need lithium levels checked and the dose adjusted. Digoxin levels are not lowered by calcitonin, although calcium changes can affect digoxin toxicity. Warfarin is not affected by calcitonin in this way. Phenytoin levels are not lowered by calcitonin.
Category: Bone and Calcium Regulators
Question 9
Which additional action does propylthiouracil have that methimazole lacks?
It blocks conversion of T4 to T3 in tissues
✓
It destroys overactive thyroid tissue
It blocks beta receptors in the heart
It replaces deficient adrenal hormones
Correct Answer
It blocks conversion of T4 to T3 in tissues
Both thionamides block synthesis of new thyroid hormone, but propylthiouracil also inhibits the conversion of T4 to the more active T3 in peripheral tissues. Destroying overactive thyroid tissue is how radioactive iodine works. Blocking beta receptors in the heart is the role of a drug such as propranolol. Replacing deficient adrenal hormones is the role of glucocorticoids.
Category: Antithyroid Drugs
Question 10
Why is a strong iodine solution given for a short time before a thyroidectomy?
To prevent wound infection after surgery
To shrink the gland and reduce its blood supply
✓
To raise thyroid hormone levels before surgery
To prevent low calcium after surgery
Correct Answer
To shrink the gland and reduce its blood supply
High doses of iodine quickly reduce thyroid hormone release and make the gland smaller, firmer and less vascular, which lowers bleeding risk during surgery. Preventing wound infection after surgery is the job of antibiotics and sterile technique. Raising thyroid hormone levels is the opposite of the goal in hyperthyroidism. Preventing low calcium after surgery depends on protecting the parathyroid glands and giving calcium if needed.
Category: Antithyroid Drugs
Question 11
What is the purpose of giving propranolol to a client with hyperthyroidism?
To block synthesis of thyroid hormone
To destroy part of the thyroid gland
To relieve rapid heart rate and tremor
✓
To replace missing thyroid hormone
Correct Answer
To relieve rapid heart rate and tremor
A beta blocker such as propranolol blunts the adrenergic symptoms of excess thyroid hormone, including tachycardia, palpitations, tremor and anxiety, while the antithyroid drug takes effect; it does not change hormone production. Blocking synthesis of thyroid hormone is the action of methimazole and propylthiouracil. Destroying part of the thyroid gland is the action of radioactive iodine. Replacing missing thyroid hormone is the treatment for hypothyroidism.
Category: Antithyroid Drugs
Question 12
A client with long-standing untreated hypothyroidism is admitted with hypothermia, hypoventilation and stupor. Which treatment does the nurse anticipate?
Oral methimazole
Oral potassium iodide
Intravenous propranolol
Intravenous thyroid hormone
✓
Correct Answer
Intravenous thyroid hormone
These findings point to myxedema coma, a life-threatening complication of severe hypothyroidism, which is treated with intravenous thyroid hormone along with supportive care and usually glucocorticoids. Oral methimazole lowers thyroid hormone and would worsen the condition. Oral potassium iodide suppresses thyroid hormone release. Intravenous propranolol slows the heart and is used for excess thyroid hormone, not a deficiency.
Category: Thyroid Replacement
Question 13
A client with Graves disease who stopped taking methimazole develops high fever, severe tachycardia, agitation and vomiting. Which complication should the nurse suspect?
Thyroid storm
✓
Myxedema coma
Adrenal crisis
Hypocalcemic tetany
Correct Answer
Thyroid storm
Thyroid storm is a rare, severe surge of thyroid hormone effects in a client with inadequately treated hyperthyroidism, causing fever, extreme tachycardia, agitation, vomiting and possible heart failure; it is reported at once. Myxedema coma is the opposite extreme of untreated hypothyroidism, with hypothermia and slowed function. Adrenal crisis causes shock and low blood pressure from cortisol deficiency. Hypocalcemic tetany causes muscle spasms and tingling from low calcium.
Category: Antithyroid Drugs
Question 14
Which oral calcium salt should be taken with meals because stomach acid improves its absorption?
Calcium citrate
Calcium carbonate
✓
Calcium gluconate
Calcium chloride
Correct Answer
Calcium carbonate
Calcium carbonate needs stomach acid to dissolve, so it is absorbed best when taken with food. Calcium citrate is absorbed well with or without food and is often preferred for clients with low stomach acid. Calcium gluconate is mainly given intravenously for acute hypocalcemia. Calcium chloride is an intravenous-only product for urgent hypocalcemia.
Category: Calcium and Vitamin D
Question 15
A client who takes alendronate also takes a calcium supplement. How should the nurse teach the client to time the calcium?
Take it with the alendronate each morning
Take it right before the alendronate
Take it later in the day, apart from the alendronate
✓
Stop calcium while taking alendronate
Correct Answer
Take it later in the day, apart from the alendronate
Calcium and other minerals bind bisphosphonates in the gut and block their absorption, so alendronate is taken alone with water and the calcium supplement is taken later in the day. Taking it with the alendronate each morning or right before it would prevent the bisphosphonate from being absorbed. Stopping calcium is wrong, because adequate calcium and vitamin D intake is part of osteoporosis treatment.
Category: Bisphosphonates
Question 16
Before a client begins long-term bisphosphonate therapy, the nurse recommends which preventive step?
An eye examination
A hearing test
A skin cancer screening
A dental examination
✓
Correct Answer
A dental examination
Bisphosphonates are linked to osteonecrosis of the jaw, especially after tooth extractions or with poor oral health, so a dental exam and any needed dental work are advised before therapy and good oral hygiene is taught. An eye examination is not a standard precaution for this drug class. A hearing test is not linked to bisphosphonate risks. A skin cancer screening is not related to these drugs.
Category: Bisphosphonates
Question 17
A client who started cinacalcet reports tingling around the mouth and muscle cramps. Which problem should the nurse suspect?
Low serum calcium
✓
High serum calcium
Low serum sodium
High serum potassium
Correct Answer
Low serum calcium
Cinacalcet lowers parathyroid hormone secretion and therefore lowers serum calcium, and perioral tingling, cramps, spasms or seizures signal hypocalcemia; calcium is checked and the provider notified. High serum calcium would cause fatigue, constipation and confusion rather than tingling and cramps. Low serum sodium causes confusion and headache and is not a typical effect of cinacalcet. High serum potassium causes weakness and dysrhythmias and is not expected from this drug.
Category: Parathyroid Drugs
Question 18
A client with heart failure who takes digoxin is started on levothyroxine for hypothyroidism. As thyroid function returns to normal, what should the nurse watch for?
Digoxin toxicity as its level rises
A weaker digoxin effect as its level falls
✓
Hypokalemia caused by levothyroxine
Heart block from added AV node slowing
Correct Answer
A weaker digoxin effect as its level falls
Serum digoxin levels can fall as a hypothyroid client becomes euthyroid, so its therapeutic effect weakens; heart failure symptoms and digoxin levels are followed, and the provider may need to raise the digoxin dose. Digoxin toxicity as its level rises is the opposite of this interaction. Hypokalemia caused by levothyroxine is not an expected effect of thyroid replacement. Heart block from added AV node slowing is not expected, because thyroid hormone tends to speed the heart rather than slow conduction.
Category: Thyroid Replacement
Question 19
A client taking calcitriol reports nausea, constipation, confusion and excessive thirst. Which imbalance should the nurse suspect?
Hypocalcemia
Hyperkalemia
Hypercalcemia
✓
Hyponatremia
Correct Answer
Hypercalcemia
Calcitriol is the active form of vitamin D and strongly increases calcium absorption, so too much causes hypercalcemia, with nausea, constipation, confusion, thirst and frequent urination; serum calcium is monitored. Hypocalcemia causes tingling, cramps and tetany instead. Hyperkalemia causes weakness and dysrhythmias and is not a calcitriol effect. Hyponatremia causes confusion but not this pattern of thirst and constipation from a vitamin D product.
Category: Calcium and Vitamin D
Question 20
A client who has taken alendronate for several years reports a new dull ache in the thigh. Which complication should the nurse suspect?
Esophageal ulcer
Kidney stone
Deep vein thrombosis
Atypical femur fracture
✓
Correct Answer
Atypical femur fracture
Long-term bisphosphonate use is linked to atypical fractures of the femur, which are often preceded by dull aching pain in the thigh or groin for weeks, so new thigh or groin pain is reported and evaluated. An esophageal ulcer causes painful swallowing or heartburn. A kidney stone causes flank pain radiating toward the groin. Deep vein thrombosis is not a recognized bisphosphonate risk.
Category: Bisphosphonates