Pharmacology 106: Ch. 31 Thyroid and Antithyroid Drugs
Which statement made by a student nurse about hypothyroidism needs correction? 1. "Hypothyroidism may lead to cretinism." 2. "Graves' disease is the most common cause of hypothyroidism." 3. "Tertiary hypothyroidism results from reduced levels of thyrotropin-releasing hormone." 4. "Secondary hypothyroidism results from reduced secretion of thyroid-stimulating hormone."
"Graves' disease is the most common cause of hypothyroidism." --Graves' disease is the most common cause of HYPERTHYROIDISM. **Hypothyroidism: Can lead to cretinism due to hyposecretion of thyroid hormone. **Tertiary hypothyroidism: Caused by reduced levels of thyrotropin-releasing hormone. **Reduced secretion of thyroid-stimulating hormone: Results in secondary hypothyroidism. P. 482
The patient receiving propylthiouracil asks the nurse, "How will this medication help relieve my symptoms?" With which would the nurse respond? 1. "It helps your thyroid gland use iodine and synthesize hormones more efficiently." 2. "It inactivates any circulating thyroid hormone, thus decreasing signs and symptoms of hyperthyroidism." 3. "It inhibits formation of new thyroid hormone, thus gradually returning your metabolism to normal." 4. "It stimulates the pituitary to secrete thyroid-stimulating hormone (TSH), which inhibits activity of the thyroid."
"It inhibits formation of new thyroid hormone, thus gradually returning your metabolism to normal." --Propylthiouracil: An Antithyroid medication used to treat hyperthyroidism. --It works by inhibiting the synthesis of new thyroid hormone. P. 484
A patient receiving propylthiouracil asks the nurse how this medication will help relieve symptoms. Which statement explains the action of the medication? 1. "Propylthiouracil helps the thyroid gland use iodine and synthesize hormones better." 2. "Propylthiouracil inactivates any circulating thyroid hormone, thus decreasing signs and symptoms of hyperthyroidism." 3. "This medication inhibits the formation of new thyroid hormone, thus gradually returning your metabolism to normal." 4. "This medication stimulates the pituitary gland to secrete thyroid-stimulating hormone, which inhibits the production of hormones by the thyroid gland."
"This medication inhibits the formation of new thyroid hormone, thus gradually returning your metabolism to normal." --Propylthiouracil: An Antithyroid medication used to treat HYPERTHYROIDISM. --Works by inhibiting the synthesis of new thyroid hormone. P. 484
During an assessment, a patient ask the nurse, "What should I do if I miss two or three doses of thyroid replacement drug in a row?" Which response would be given by the nurse? 1. "You can take the dose immediately when you remember it." 2. "Skip the missed dose and resume your usual dosage schedule." 3. "You should consult your primary health care provider immediately." 4. "If it is almost time for your next dose; at that time, take a double dose of the drug."
"You should consult your primary health care provider immediately." --This helps the PCP plan effective treatment and avoid probable complications by modifying the dosage regimen. --Taking doses, skipping a dose, or taking a double doses can cause adverse effects and the treatment may not be effective. P. 485
A patient who is taking propylthiouracil complains, "It's been 10 days since I started taking the medication, but my hunger is still not suppressed." Which explanation would the nurse provide? 1. "Increase the amount of fiber in your diet." 2. "Your hunger will subside in another 10 days." 3. "Take the drug on an empty stomach before breakfast." 4. "Make an appointment with your PCP."
"Your hunger will subside in another 10 days." --The therapeutic benefits are achieved after 2 weeks, therefore the increased hunger (symptom of hyperthyroidism) will be reduced eventually. **Antithyroid drugs are best prescribed to be taken after meals to prevent gastric irritation. **An appointment with the PCP will be scheduled if the symptoms of hyperthyroidism are prevalent after the patient has been on therapy for a minimum of 2 weeks. P. 485
Which statement describes what the nurse would teach a patient who has a first-time prescription for the antithyroid drug propylthiouracil? SATA. 1. "You need to be aware of the manifestations of hypothyroidism." 2. "Take the medication along with a meal to prevent stomach upset." 3. "You need to avoid eating salt, shellfish, and foods high in iodine." 4. "This drug is given to raise the thyroid hormone levels in your blood." 5. "Take the medication daily on an empty stomach to reduce liver damage."
1, 2, 3 -"You need to be aware of the manifestations of hypothyroidism." -"Take the medication along with a meal to prevent stomach upset." -"You need to avoid eating salt, shellfish, and foods high in iodine." **Propylthiouracil: A thioamide antithyroid drug used for hyperthyroidism. **It has to be administered for at least 2 weeks so that the manifesting symptoms improve. P. 485
Which symptoms are clinical indicators of Graves' disease? SATA. 1. Diarrhea 2. Flushing 3. Bradycardia 4. Heat intolerance 5. Cold intolerance 6. Altered menstrual flow
1, 2, 4, 6 -Diarrhea -Flushing -Heat intolerance -Altered menstrual flow --Graves' disease: A type of hyperthyroidism characterized by excessive thyroid hormone secretion, resulting in an increase in the metabolic rate. --Additional clinical manifestations include: Increased appetite, muscle weakness, fatigue, palpitations, irritability, nervousness, and sleep disorders. P. 482
Which are the symptoms of hypothyroidism? Select all that apply. 1. Depression 2. Cold intolerance 3. Increased appetite 4. Altered menstrual cycle 5. Dry, brittle hair and nails
1, 2, 5 -Depression -Cold intolerance -Dry, brittle hair and nails. --Hypothyroidism: Decreased levels of thyroid hormones, resulting in symptoms. **Increased appetite and altered menstrual cycle: Symptoms of hyperthyroidism (Increased levels of thyroid hormones). P. 482
Which are the adverse effects of antithyroid medication? SATA. 1. Vertigo 2. Cramps 3. Tremor 4. Leukopenia 5. Loss of taste
1, 4, 5 -Vertigo -Leukopenia -Loss of taste **Cramps and tremors are adverse effects of thyroid medications. P. 484
Which are the adverse effects of thyroid replacement drugs? SATA. 1. Fatigue 2. Chest pain 3. Palpitations 4. Weight gain 5. Cold intolerance
2 & 3 -Chest pain -Palpitations **Fatigue, weight gain, and cold intolerance: Symptoms of hypothyroidism. P. 483
Which genitourinary adverse effects does the nurse expect in the patient who is on therapy with antithyroid medication? SATA. 1. Bleeding 2. Smoky urine 3. Decreased urinary output 4. Increased blood urea nitrogen 5. Increased serum creatinine levels
2 & 3 -Smoky urine -Decreased urinary output --Bleeding is a hematologic adverse effect. --Increased blood urea nitrogen & increased serum creatinine levels are renal adverse effects. P. 484
Which information would the nurse include when teaching a patient with a new prescription of levothyroxine? Select all that apply. 1. Avoid the use of iodized salt or shellfish in the diet. 2. Take the medication 30 minutes prior to breakfast. 3. Take the medication with food at the evening meal. 4. Administer with an antacid if stomach upset occurs. 5. Check your heart rate prior to administration of the drug.
2 & 5 -Take the medication 30 minutes prior to breakfast. -Check your heart rate prior to administration of the drug. --The medication should be taken without any other medications or food. --The drug may cause tachycardia. --Antacids are not taken with levothyroxine due to it interfering with absorption. **Methimazole: Avoid use of iodized salt or shellfish. P. 483
The nurse is assessing a patient who has been prescribed thyroid replacement drugs for the first time. The nurse asks the patient to take the daily medication every morning on an empty stomach. Which are the reasons for this instruction? SATA. 1. To minimize the therapeutic effects. 2. To decrease the likelihood of insomnia. 3. To increase the likelihood of daytime sleep. 4. To decrease the risk of drug-drug interactions. 5. To maintain consistent blood levels of the drug.
2, 4, 5 -To decrease the likelihood of insomnia. -To decrease the risk of drug-drug interactions. -To maintain consistent blood levels of the drug. P. 487
Which assessment findings would the nurse expect in a child who has cretinism? SATA. 1. Weight gain 2. Heat intolerance 3. Mental retardation 4. Low metabolic rate 5. Dullness of the skin
3 & 4 -Mental retardation -Low metabolic rate --Hyposecretion of thyroid hormone at a young stage may lead to cretinism. -Characteristics of cretinism: Low metabolic rate, retarded growth and sexual development, and possible mental retardation. P.
Which process is characterized by destruction of the thyroid gland? 1. Ablation 2. Desiccation 3. Thyroid storm 4. Thyroidectomy
Ablation. --Destroys the thyroid gland by using radioactive iodine. **Desiccation: The drying process to prepare the thyroid . **Thyroid storm: Exacerbation of hyperthyroidism symptoms. **Thyroidectomy: The surgical resection of the thyroid gland. P. 484
The PCP prescribes a drug for a patient who is underweight and shows symptoms of diarrhea, increased appetite, and flushing. Which other drug in the patient's medication history would be of concern for the nurse? 1. Antidiabetics 2. Antihistamines 3. Anticoagulants 4. Beta-lactam antibiotics
Anticoagulants. --These symptoms are consequences of increased metabolism caused by hyperactivity of the thyroid gland. --Antithyroids are used in treating this condition, and the dosage is adjusted when the patient is already taking anticoagulants. **Antidiabetics: Contraindicated with thyroid drugs, not antithyroids. P. 487
The nurse is caring for a patient who has hyperthyroidism. The health care provider has prescribed methimazole. Which assessment is a priority? 1. Assess the patient's urine output. 2. Assess signs of cardiac irregularities. 3. Assess the patient's serum creatinine levels. 4. Assess signs and symptoms of thyroid storm.
Assess signs and symptoms of thyroid storm. --Thyroid storm is an exacerbation of hyperthyroidism symptoms. --Thyroid storm happens when the thyroid gland suddenly releases large amounts of thyroid hormone in a short period of time. **Urine output: Assessed after the therapy due to methimazole (Antithyroid drug) decreases urine output. **Signs of cardiac irregularities: Assessed for in thyroid drug usage. **Serum creatinine levels: Assessed after the therapy, due to methimazole increases serum creatinine levels. P. 485
The nurse is taking the history of a female patient who has been prescribed thyroid replacement drugs. The nurse finds that the patient is receiving estrogen supplements as part of hormone replacement therapy. Which possible drug interaction may the nurse anticipate? 1. Increased blood glucose level 2. Decreased blood glucose level 3. Decreased thyroid drug activity 4. Increased estrogen levels in the blood.
Decreased thyroid drug activity. --Thyroid drugs + Estrogen supplements = reduced thyroid activity which destabilizes the thyroid treatment. **Alterations in glucose levels: Occur when diabetic patients take oral hypoglycemic medications and thyroid medication. P. 483
The nurse reviews a patient's lab report and notes elevated thyroxin levels. Which condition does the patient have? 1. Goiter 2. Cretinism 3.Myxedma 4. Graves' disease
Graves' disease. --Elevated thyroxin levels signify hyperthyroidism, which is observed with Graves' disease. **Goiter: Enlargement of the thyroid gland caused by overstimulation by elevated thyroid-stimulating hormone levels. **Cretinism: A syndrome characterized by low metabolic rate, caused by hyposecretion of thyroid hormone during youth. **Myxedema: Condition caused by hyposecretion of thyroid hormone as an adult. P 482.
The nurse is assessing a patient who has been taking propylthiouracil for the past 2 weeks and has normal thyroid-stimulating hormone (TSH) levels. Which symptom would the nurse primarily monitor the patient? 1. Loss of appetite 2. Cold intolerance 3. Heart palpitations 4. Unexplained weight gain
Heart palpitations. --Thyroid storm: Hyperthyroid symptoms characterized by hypertension & palpitations. --This is a life-threatening condition. --The patient will monitor for symptoms of hyperthyroidism (heart palpitations). P. 485
The nurse is assessing a patient who has loss of memory, hair loss, and yellow discoloration of the skin. Which laboratory findings would the nurse suspect from these observations? 1. Increased thyroxine levels 2. Increased calcitonin levels 3. Increased triiodothyronine levels 4. Increased thyroid-stimulating hormone
Increased thyroid-stimulating hormone. --These symptoms indicate the patient has myxedema, which is caused by insufficient production of thyroid hormone, and the patient would need to take thyroid hormones, but this condition does elevate thyroid-stimulating hormone (TSH) levels (Due to reduced T3 & T4). --Calcitonin levels may also be reduced. P. 486
The nurse is assessing a patient undergoing levothyroxine therapy. Which symptom makes the nurse suspect excessive thyroid replacement? 1. Irritability 2. Drowsiness 3. Bradycardia 4. Intolerance to cold
Irritability. --A symptom of hyperthyroidism. **Drowsiness, bradycardia, and intolerance to cold: Signs of HYPOTHYROIDISM. P. 487
The nurse is caring for a patient who has just started taking levothyroxine. Which assessment finding is necessary for the nurse to address? 1. Irritability 2. Brittle nails 3. Intolerance of cold. 4. Weight gain of 3 pounds in the last week.
Irritability. --A symptom of hyperthyroidism. --This could be a sign that the medication dosage is too high. **Brittle nails, intolerance to cold, and weight gain = normal symptoms of hypothyroidism. P. 483
The health care provider prescribes radioactive iodine to an adult patient who has thyroid cancer. Which is the reason for prescribing this drug to the patient? 1. It acts as a prophylactic agent against radiation exposure. 2. It takes up beta rays into the follicles of the thyroid gland. 3. It increases the cellular metabolic rate and oxygen consumption. 4. It inhibits the conversion of T4 to T3 in the peripheral circulation.
It takes up beta rays into the follicles of the thyroid gland. --Radioactive iodine: Commonly used for both hyperthyroidism and thyroid cancer. --It emits destructive beta rays into the follicles of the thyroid gland, destroying it in a process called ablation. **Potassium iodide: Used as prophylaxis for radiation exposure. **Thyroid replacement drugs: Increase the cellular metabolic rate and oxygen consumption as the endogenous thyroid hormones, rather than Antithyroid drugs. **Propylthiouracil: Inhibits the conversion of T4 to T3 in the peripheral circulation to decrease the level of thyroid hormone. P. 484
The nurse prepares to administer an initial dose of propylthiouracil to a patient with toxic nodular disease of the thyroid gland. Which baseline patient assessment is a priority for the nurse before the start of therapy? 1. Skin condition 2. Leukocyte count 3. Size of the thyroid 4. Coloration of the urine
Leukocyte count. --WBC count is ordered to establish a baseline for future comparison due to propylthiouracil can cause bone marrow suppression, leading to agranulocytosis. --Priority baseline assessment because agranulocytosis impairs the patient's immune system and increases the risk of severe bacterial and fungal infections. **Side effects of Propylthiouracil: Rash, pruritus, an enlarged thyroid, and smoky-colored urine. P. 484-485
Which medication is used to treat myxedema coma? 1. Liotrix 2. Methimazole 3. Levothyroxine 4. Propylthiouracil
Levothyroxine. --A synthetic thyroid hormone (T4). **Liotrix: A thyroid supplement used in the treatment of hypothyroidism. **Methimazole and propylthiouracil: Two thioamide derivatives used in the treatment of hyperthyroidism. P. 482
The nurse is caring for a patient who has congenital hypothyroidism. Which medication would the nurse expect the primary health care provider to prescribe? 1. Liotrix 2. Methimazole 3. Levothyroxine 4. Propylthiouracil
Levothyroxine. --A thyroid drug used to treat congenital hypothyroidism. **Liotrix: A thyroid drug used to treat hypothyroidism but not congenital hypothyroidism. **Methimazole & propylthiouracil: Antithyroid drugs used to treat hyperthyroidism. P. 483
A patient walks into a clinic, shivering and looking depressed and tired. The caregiver reports, "The patient was normal until last month but then suddenly started to gain weight." Further assessment from the primary health care provider shows brittle hair and fingers. Which medication would the nurse expect in the patient's prescription? 1. Liotrix 50 mg/day orally. 2. Methimazole 20 mg/day orally. 3. Propylthiouracil 300 mg/day orally. 4. Levothyroxine 300 mcg intravenous (IV)
Liotrix 50 mg/day orally. --Weight gain, depression, fatigue, brittle fingers and hair, and cold intolerance are symptoms associated with hypothyroidism. --The nurse should expect a thyroid drug: Liotrix 50 mg/day is a thyroid drug. **Methimazole & propylthiouracil: Antithyroid drugs prescribed for hyperthyroidism. **Levothyroxine: Thyroid drug prescribed IV during myxedema coma (a severe condition of hypothyroidism). P. 482, 483
The nurse teaches a nursing student about liotrix. Which statement made by the nurse is appropriate? 1. Liotrix contains T3 alone. 2. Liotrix contains T4 alone. 3. Liotrix contains T4 and T3 in a 4:1 ratio. 4. Liotrix contains T4 combined with calcium.
Liotrix contains T4 and T3 in a 4:1 ratio. --Liotrix is used to treat hypothyroidism. --It is used to replace the diminished hormone levels of the body. **Levothyroxine: Contains only T4. P. 482
The nurse is assessing a pregnant patient in the second trimester who has hyperthyroid activity. Which would the nurse expect the health care provider to order? 1. Methimazole 2. Propylthiouracil 3. Avoid the drug for 2 weeks. 4. Avoid folic acid supplements
Methimazole. **Propylthiouracil: An antithyroid drug that is prescribed in the first trimester of pregnancy. (Antithyroid drugs are prescribed for a lifetime and are not discontinued). **Folic acid is important for pregnant women and should not be stopped. P. 484
A patient with a thyroid disorder states, "I am unable to distinguish between the tastes of different foods." Which medication would the nurse expect is responsible for this condition? 1. Liotrix 2. Methimazole 3. Levothyroxine 4. Desiccated thyroid
Methimazole. --An Antithyroid drug, where the adverse effects is loss of taste. **Liotrix, levothyroxine, and desiccated thyroid: Thyroid drugs associated with loss of hair but not with loss of taste. P. 484
A patient with a thyroid disorder states, "I am unable to distinguish between the tastes of different foods." Which medication would the nurse expect is responsible for this condition? 1. Liotrix 2. Methimazole 3. Levothyroxine 4. Desiccated thyroid
Methimazole. --An antithyroid drug. **Liotrix, levothyroxine, and desiccated thyroid: Thyroid drugs associated with loss of hair. P. 484
A patient who has been on propylthiouracil for 2 weeks approaches the nurse for a routine medical checkup. Which is a priority assessment for this patient? 1. Platelet count 2. Glucose levels 3. Calcium levels 4. Creatinine levels
Platelet count. --Thrombocytopenia (Reduced platelet count) is one of the many side effects of antithyroid drugs. **Glucose levels are altered when thyroid drugs are administered. **Patient's creatinine levels are measured when renal impairment is suspected. **Propylthiouracil may affect hepatic activity. P. 484
A patient with stage III laryngeal cancer underwent laryngectomy with concurrent removal of the thyroid gland. Which type of hypothyroidism will occur in this case? 1. Primary hypothyroidism 2. Tertiary hypothyroidism 3. Secondary hypothyroidism 4. Quaternary hypothyroidism
Primary hypothyroidism. --There is no release of thyroid hormones due to the removal of the thyroid gland. --Primary hypothyroidism: Stems from an abnormality in the thyroid gland (most common type of hypothyroidism). **Secondary hypothyroidism: Caused by an abnormal release of thyroid-stimulating hormone (TSH) by the pituitary gland. --> TSH is needed to trigger the release of stored thyroid hormones. **Tertiary hypothyroidism: Caused by the reduced secretion of thyrotropin-releasing hormone from the hypothalamus. P. 482
A patient who has been taking levothyroxine is experiencing weight loss, tremors, and hypertension. Which pharmacokinetic property of levothyroxine is responsible for causing toxic manifestations? 1. Onset of action of 1 to 3 days. 2. Prolonged half-life of 10 days. 3. Duration of action of 12 hours. 4. Intravenous administration of the drug.
Prolonged half-life of 10 days. --The drug remains in the body for 10 days and shows its effects, which results in symptoms of toxicity. --Duration of action of levothyroxine is 24 hours when given orally. --> The IV route is normally 50% less than the oral route. P. 483
Which medication is used to treat hyperthyroidism during the first trimester of pregnancy? 1. Liotrix 2. Methimazole 3. Levothyroxine 4. Propylthiouracil
Propylthiouracil. --An antithyroid medication used in the first trimester of pregnancy to treat hyperthyroidism. **Methimazole: Recommended after the first trimester of pregnancy due to it causing fetal adverse effects like: scalp abnormalities, goiter, and cretinism. **Liotrix & Levothyroxine: Hypothyroid medications used to treat hypothyroidism. P. 484
The nurse is providing prenatal counseling for a patient who has hyperthyroidism and is prescribed methimazole. The nurse instructs the patient to discuss discontinuing the medication with the provider in the event of conception. Which fetal abnormality is the nurse trying to prevent? 1. Scalp abnormality 2. Eating abnormality 3. Walking abnormality 4. Breathing abnormality
Scalp abnormality. (Occur when methimazole is used during the second and third trimesters of the pregnancy). --Methimazole: Classified as a pregnancy category D drug. P. 484
A patient is taking an antithyroid medication. Which foods would the nurse teach the patient to avoid eating? 1. Ham and cheese omelet, rye toast with butter, orange juice. 2. Hamburger on sesame roll, salad with French dressing, milk. 3. Chicken salad sandwich with mayonnaise, vegetable soup, milk. 4. Shrimp cocktail, boiled lobster, spinach salad without dressing, milk.
Shrimp cocktail, boiled lobster, spinach salad without dressing, milk. --Seafood contains high amounts of iodine. --Patient taking an antithyroid medication should avoid foods high in iodine. P. 487
In the process of thyroid hormone development, what happens after the synthesis of T3 and T4? 1. Iodine is sequestered in the thyroid gland. 2. Triiodothyronine is released into the blood. 3. Thyroxine is released into the blood slowly. 4. T3 and T4 are stored in a complex with thyroglobulin.
T3 and T4 are stored in a complex with thyroglobulin. --Once synthesized T3 (Triiodothyronine) and T4 (Thyroxine) are stored in the follicle of the thyroid gland with thyroglobulin (A protein that contains tyrosine and an amino acid). **Iodine sequestration in the thyroid gland occurs earl in the formation of thyroxine. **T3 and T4 are not released into the blood until thyroid-stimulating hormone (TSH) signals the need for them. P. 482
The nurse counsels a patient about preventing insomnia caused by liotrix. Which information would the nurse provide? 1. Take the drug before breakfast. 2. Take the drug along with meals. 3. Take the drug 1 hour after meals. 4. Take a nap during the day, after lunch.
Take the drug before breakfast. --The drug activity is better achieved on an empty stomach, therefore it would be taken before a meal. P. 487
During an assessment of a patient with hyperthyroidism, the nurse learns that the patient's provider has recommended thyroidectomy. Which statement could describe the reason for opting for such treatment for the patient? 1. The patient is obese 2. The patient is elderly 3. The patient is diabetic 4. The patient is pregnant.
The patient is pregnant. --Antithyroid medications are prescribed for hyperthyroidism, but they have teratogenic effects. --Thyroidectomy is recommended for patients who are intolerant to, or whose conditions contraindicate, antithyroid medications. P. 485, 484