USMLE rx Endocrine missed Qs
A 21-year-old college student comes for evaluation because of worsening palpitations and weight loss during the past 2 months. She is six weeks pregnant. Her temperature is 37.3°C (99.1°F), blood pressure is 124/82 mm Hg, and pulse is 115/min. The exam shows a smooth, nontender goiter. After additional testing, she is begun on propranolol, and her symptoms improve in the next two days. Which of the following is the most appropriate next step in therapy? A.Fluoxetine B.Levothyroxine C.Methimazole D.Prednisone E.Propylthiouracil F.Radioactive iodine
Propylthiouracil. Hyperthyroidism can be managed with β-blockers, anti-thyroid drugs (methimazole or propylthiouracil), thyroid-ablating radioactive iodine. Methimazole is contraindicated in the first trimester of pregnancy, and radiation throughout pregnancy. i incorrectly chose Methimazole, which blocks the oxidation of iodine in the thyroid gland, which inhibits the synthesis of thyroid hormones (T3and T4). Methimazole is contraindicated in this patient because she is likely pregnant, given her sexual history and her positive urine pregnancy test (elevated urine hCG). Because methimazole is contraindicated during the first trimester due to its association with congenital malformations.
A 44-year-old woman is referred to an endocrinologist after her lab results showed an elevated glucose level. She reports increased fatigue, sweating, and weight gain. She also notes an inability to wear his wedding ring lately because it no longer fits and states that she has purchased new shoes since the old ones were too small. She complains of difficulties in getting a good night's sleep, which her husband attributes to his recent bouts of snoring. Her vital signs show a blood pressure of 150/90 mm Hg, temperature of 98.0°F (36.6°C), and heart rate of 80/min. The physical examination is notable for decreased peripheral vision, a laterally displaced PMI, and an S4 heart sound. The serum glucose is 300 mg/dL. An echocardiogram shows diastolic dysfunction and aortic regurgitation. An anaesthesia consultation deems her unable to undergo surgery due to her cardiac function. Which of the following is the most appropriate next step in treatment? A.Methimazole B.Octreotide C.Prednisone D.Raloxifene E.Thyroxine
B.Octreotide. Coarsening of facial features, macroglossia, thickened fingers, and hyperglycemia are signs of excessive growth hormone synthesis in acromegaly, which can be treated with octreotide, a synthetic octapeptide analog of somatostatin. patient presents with elevated glucose, weight gain, impaired peripheral vision, sleep apnea, heart failure, and increased hand and foot size. These symptoms are likely explained by a diagnosis of acromegaly, Other symptoms of acromegaly include coarsening of facial features, joint pain, and sweating. Increased heart size, diastolic heart failure and elevated blood pressure are major complications of acromegaly, with heart failure being the most common cause of death in these patients. HF is why this patient could not undergo pituitary surgery.
A 32-year-old woman comes for evaluation because of a sore throat, fever, and chills. She reports feeling "under the weather" for the past few weeks. She works as an elementary school teacher and says that some of her students have been ill. She has a history of Graves disease managed with medications. Temperature is 38.3°C (101°F), pulse is 110/min, and blood pressure is 118/83 mm Hg. Physical examination shows no abnormalities. Laboratory studies show:RBC: 4.9 million/mm3Hemoglobin: 14.7 g/dLWBC: 9,000/mm3Absolute neutrophil count: 1300/mm3Thyroid-stimulating hormone: 2.4 μU/LThyroxine (T4): 8.6 μg/dL Which of the following is the most likely cause of this patient's current symptoms? A.Acute myeloid leukemia B.Aplastic anemia C.Autoimmune disease D.Drug-induced neutropenia E.Thyroid storm F.Virus-induced neutropenia
D.Drug-induced neutropenia. Antithyroid drugs, such as methimazole and propylthiouracil, can cause agranulocytosis, which is defined by an absolute neutrophil count of less than 1500/mm3. Patients present with generalized symptoms of infection. Treatment involves immediate cessation of offending drug, and broad-spectrum intravenous antibiotics. sore throat, chills, and fever, which are non-specific signs and symptoms of infection. She has a history of Graves disease that is managed well with medications as evidenced by her normal thyroid-stimulating hormone and thyroxine values. Her white blood cell count and decreased neutrophil count are concerning for agranulocytosis, which likely led to infection
A 17-year-old girl presents to the physician due to progressive fatigue, weakness, and weight loss. She has recently lost 11 kg (25 lb) and is below the 50th percentile in weight for her height. Her heart rate is 86/min, respiratory rate is 16/min, and temperature is 37°C (98.6°F). Her blood pressure is 122/80 mm Hg while supine and 100/72 mm Hg upon standing. Physical examination reveals scant pubic and axillary hair. Her skin has a patchy bronze coloring although she does not recall excessive sun exposure. Laboratory studies show the following: Na: 133 mEq/L K+: 5.4 mEq/L HCO3-: 20 mEq/L Creatinine: 1.2 mg/dL Glucose:45 mg/dL Which of the following medications would most effectively correct the patient's electrolyte disorders? A.Albuterol B.Demeclocycline C.Dexamethasone D.Fludrocortisone E.Insulin with glucose F.Leuprolide G.Spironolactone
D.Fludrocortisone Addison disease manifests with hypotension, hyperkalemia, and hyperpigmentation, due to an inability of the adrenal glands to produce glucocorticoid and mineralocorticoid hormones. Treatment includes glucocorticoids and exogenous mineralocorticoids (fludrocortisone=synthetic analog of aldosterone). atient presents with sexual immaturity (scant pubic and axillary hair), bronze discoloration of the skin, orthostatic hypotension (systolic drop of at least 20 mm Hg on standing), hyperpigmentation, hypoglycemia, hyperkalemia, and metabolic acidosis. These are clinical features of Addison disease, or primary adrenal insufficiency. treatment of Addison disease requires replacement of the adrenal hormones, most importantly glucocorticoids, using hydrocortisone or dexamethasone. This will correct the hypoglycemia and hypotension. However, the hyperkalemia and hyponatremia will respond best to a mineralocorticoid like fludrocortisone. Fludrocortisone acts on mineralocorticoid receptors to increase sodium and water uptake in the kidney tubules. This will correct hyperkalemia, hyponatremia, and metabolic acidosis.
A 4-year-old boy is brought to the clinic for an annual check-up. He had cardiac surgery at 6 months of age and has been followed up by a pediatric cardiologist since that time. The boy has also had recurrent infections with opportunistic pathogens, including an episode of Pneumocystis jirovecii pneumonia. Physical examination reveals a unilateral cleft lip and hard palate on the left. Which serum electrolyte abnormality is most likely to be found in this patient? A.Hypercalcemia B.Hyperkalemia C.Hypernatremia D.Hypocalcemia E.Hypokalemia F.Hyponatremia
Deletions of chromosome 22q11 lead to syndromes characterized by cleft palate, abnormal facies, thymic aplasia, cardiac defects, and hypocalcemia. DiGeorge syndrome is the result of one such deletion that specifically includes thymic, parathyroid, and cardiac defects. These syndromes can be remembered with the CATCH-22 mnemonic: Cleft palate, Abnormal facies, Thymic aplasia, Cardiac defects, Hypocalcemia, and deletion of chromosome 22. HY topic 70 NBME This child has a history of a cardiac surgery as an infant, recurrent infections, and a cleft lip and palate, which are all consistent with DiGeorge syndrome. loss of a critical region responsible for the development of the third and fourth pharyngeal pouches. These embryonic structures give rise to the thymus and parathyroid glands. DiGeorge syndrome specifically includes thymic, parathyroid, and cardiac defects. Patients with absent or defective parathyroid glands would be expected to have hypocalcemia, which can be severe and even cause tetanic seizures
A 34-year-old man who has ulcerative colitis is hospitalized after developing intense abdominal pain and passing bright red loose stools. He has been taking 5-aminosalicylate with good control of his symptoms until now. While at the hospital, he is prescribed a medication to reduce the inflammation and achieve remission of his acute flare. The physician recommends initiating a 60-mg dose with a slow taper in daily dosing until he is completely weaned off the medication. Which of the following adverse effects is most likely to arise from long-term maintenance use of the newly prescribed medication? A.Adrenal hyperplasia B.Agranulocytosis C.Hepatotoxicity D.Hip fracture E.Immune reconstitution inflammatory syndrome
Hip fracture. An acute flare of ulcerative colitis is medically managed with prednisone taper. Long-term corticosteroid therapy at a maintenance dose increases the risk of Cushing syndrome and related osteoporotic fractures, as well as a number of other serious conditions. Continuous treatment with 10 mg of prednisone per day for greater than 90 days has also been shown to increase the risk of hip fractures (due to osteoporosis) by greater than 7-fold and vertebral fractures greater than 17-fold. Risk factors for glucocorticoid-induced osteoporosis include advanced age (>60 years old); low body mass index; underlying disease, for example, inflammatory bowel disease, as seen in this patient; high glucocorticoid dose; and pre-existing low bone mineral density. his physician has ordered that the dose be tapered on a daily basis to achieve remission and to avoid the risks associated with long-term maintenance therapy.
