A 22-year-old woman comes to the office due to palpitations, weight loss, and insomnia.  She has lost 7 kg (15.4 lb) in the past 3 months.  The patient has no other medical problems and takes no medication.  She does not use tobacco, alcohol, or illicit drugs.  Blood pressure is 130/80 mm Hg and pulse is 104/min and regular.  The thyroid gland is diffusely enlarged and nontender on palpation.  Laboratory studies show markedly decreased serum TSH and elevated thyroxine levels.  Methimazole monotherapy is initiated.  Two months later, her symptoms had resolved.  The treatment most likely improved this patient’s condition by directly inhibiting which of the following processes?

A 34-year-old man comes to the office with his girlfriend for follow-up of type 1 diabetes mellitus.  He was diagnosed 15 years ago and is currently treated with a combination of basal and rapid-acting insulin injections.  The patient has been experiencing intermittent episodes of hypoglycemia with a blood glucose of 35-54 mg/dL.  Two weeks ago, he was taken to the emergency department after passing out due to low glucose levels.  The patient is prescribed an injectable medication to be administered at home by a caregiver when hypoglycemia is associated with impaired consciousness.  This medication rapidly improves hypoglycemia by which of the following mechanisms?

A 46-year-old woman comes to the office due to frequent episodes of headache, nausea, sweating, and a feeling as if she is going to pass out.  The patient has had 3 such episodes in the past 2 weeks, with symptoms occurring when she skips a meal.  During the most recent episode, finger-stick glucose was 50 mg/dL.  She was diagnosed with type 2 diabetes mellitus 3 years ago and initially treated with metformin monotherapy; glipizide was added 3 months ago due to inadequate glycemic control.  The patient has no other medical conditions.  Vital signs are within normal limits and physical examination shows no abnormalities.  Hemoglobin A1c is 6.9%.  The medication most likely responsible for this patient’s current symptoms works by targeting which of the following?

A 44-year-old man comes to the office for follow-up of type 2 diabetes mellitus.  He was diagnosed 4 years ago and has since been taking metformin.  Six months ago, a new antidiabetic agent was added because of suboptimal glycemic control.  Today, the patient is pleased because he has unintentionally lost 7 kg (15.4 lb).  His only symptoms are occasional nausea, vomiting, and a prolonged sensation of fullness after eating.  Vital signs are within normal limits.  BMI is 34 kg/m².  Physical examination reveals normal heart and lung sounds, a nontender abdomen, and normal deep tendon reflexes.  Laboratory testing shows normal renal function and a hemoglobin A1c of 7.2%.  If this patient’s weight loss is due to the new medication, which of the following agents is most likely responsible?

A 54-year-old woman comes to the office for evaluation of elevated blood glucose.  The patient was recently seen at an urgent care center, where she was found to have a nonfasting blood glucose level of 190 mg/dL.  Medical history is insignificant, although she has not seen a physician for several years.  She does not use tobacco or alcohol.  BMI is 31.5 kg/m².  Physical examination shows no abnormalities.  Hemoglobin A1c is 8.5% and fasting plasma glucose level is 146 mg/dL.  Recommendations for dietary modification and exercise are provided, and pharmacotherapy with metformin is planned.  Which of the following laboratory tests should be obtained prior to starting this medication?

A 28-year-old woman is treated with high-dose prednisone for severe lupus nephritis.  Several hours after therapy is initiated, she becomes very agitated and delusional.  Blood pressure is 130/70 mm Hg and heart rate is 110/min.  A basic metabolic profile, complete blood cell (CBC) count, and urinalysis are obtained.  The CBC differential is expected to show an increase in which of the following as a result of this patient’s therapy?

In a series of animal experiments, the insulin concentration in the pancreatic veins is measured after the administration of various agents.  Epinephrine administration is found to cause a decrease in insulin levels.  However, after pretreatment with Drug A, epinephrine injection causes a paradoxical increase in insulin concentration.  Which of the following receptors does Drug A most likely block?

A nuclear waste disposal plant suffers a containment failure and several grams of iodine-131 are released into the local environment.  A number of workers are believed to have been exposed to dangerous levels of the radioactive material.  Which of the following should be immediately administered to help prevent tissue damage in these individuals?

A 76-year-old woman is brought to the hospital after her daughter found her unresponsive in the morning.  The patient and her daughter walked extensively during a family outing the previous day; the patient then skipped dinner and went to bed as soon as they returned home.  Medical history includes type 2 diabetes mellitus managed with an oral medication.  Blood pressure is 140/80 mm Hg and pulse is 102/min.  The patient is diaphoretic and responds only to pain.  Blood glucose is 34 mg/dL.  Her condition rapidly improves after administration of an intravenous bolus of dextrose, but she becomes confused again several hours later.  Repeat blood glucose is 39 mg/dL.  Which of the following medications is the most likely cause of this patient’s current condition?

A 64-year-old woman is brought to the emergency department due to confusion and lethargy.  The patient was asymptomatic when her husband left for work in the morning, but when he arrived home, he found her in bed, weak and disoriented.  The patient’s medical conditions include type 2 diabetes mellitus and hypertension, for which she takes multiple medications.  She does not use tobacco, alcohol, or recreational drugs.  Temperature is 37 C (98.6 F), blood pressure is 140/70 mm Hg, pulse is 74/min, and respirations are 18/min.  On physical examination, the patient is somnolent but withdraws all extremities to pain.  Laboratory testing shows an elevated serum C-peptide level.  If this patient’s current condition is due to an antidiabetic drug, which of the following is the most likely culprit agent?

A 35-year-old woman comes to the emergency department due to a “racing heart” and shortness of breath.  She has had insomnia and increasing anxiety for the past several weeks.  The patient has no prior medical problems and takes no medications.  She has no drug allergies and does not use tobacco, alcohol, or illicit drugs.  Blood pressure is 140/70 mm Hg and pulse is 120/min.  Physical examination shows a diffusely enlarged, warm thyroid gland.  There is a fine tremor in her outstretched hands.  ECG shows sinus tachycardia.  Serum TSH is decreased and free thyroxine (T4) is increased.  The patient is treated with multiple drugs, including propranolol.  In addition to its beta-adrenergic receptor-blocking activity, this drug is likely to decrease which of the following?

A 50-year-old woman enrolls in a clinical trial testing a medication for type 2 diabetes mellitus that may slow the progression of or reverse nonalcoholic steatohepatitis (NASH).  Medical history includes type 2 diabetes mellitus and NASH, which was diagnosed a year ago by biopsy.  Medications include metformin, atorvastatin, and aspirin.  Laboratory studies show a fasting glucose of 155 mg/dL, hemoglobin A1c of 8.2%, ALT of 85 U/L, and AST of 74 U/L.  The study drug will be taken in addition to metformin to enhance glycemic control, and markers for NASH-related disease activity will be measured at 12 months.  The study drug activates peroxisome proliferator–activated receptor gamma, a nuclear receptor and transcription factor.  Activation of this receptor would most likely result in which of the following metabolic changes?

A 28-year-old woman comes to the office due to progressively worsening eye irritation and double vision over the last 2 months.  She also reports unintentional weight loss, mood swings, and palpitations.  The patient has no prior medical problems and takes no medications.  She has no known drug allergies and does not use tobacco, alcohol, or illicit drugs.  Blood pressure is 140/70 mm Hg, and pulse is 110/min and regular.  Physical examination shows bilateral conjunctival redness and severe proptosis.  Appropriate therapy is begun.  On a follow-up visit 4 weeks later, her eye symptoms have improved, and examination reveals a small decrease in proptosis with no redness.  The drug that improved her ocular symptoms most likely did so by affecting which of the following?

A 22-year-old woman comes to the emergency department due to fatigue and sore throat for the past few days.  The throat discomfort has caused her to be unable to eat or drink without significant pain.  Acetaminophen improves the pain slightly, but her oral intake has been poor.  The patient recently started taking antithyroid medication for Graves disease.  She has no other medical conditions and does not use tobacco, alcohol, or recreational drugs.  Weight is 67 kg (148 lb), decreased from 68.5 kg (151 lb) a week ago.  Temperature is 38.9 C (102 F), blood pressure is 102/68 mm Hg, and pulse is 130/min.  Physical examination shows an erythematous pharynx with shallow mucosal ulcerations and a normal-sized thyroid.  Mucous membranes appear dry.  The abdomen is soft and nontender.  No tremor is seen with outstretching of the hands.  Which of the following is the most likely cause of this patient’s current condition?

A 42-year-old woman with Graves disease is hospitalized for elective total thyroidectomy.  Her hyperthyroid symptoms have been controlled with methimazole and propranolol, but she still has a goiter.  The patient has no other medical problems.  She undergoes total thyroidectomy without any immediate operative complications and feels well the next day.  Laboratory results are as follows:

Preoperative electrolyte values were within normal limits.  Which of the following medications should be started in this patient?

A 48-year-old man comes to establish care after moving to a new state.  He feels well and has no symptoms.  The patient has a history of type 2 diabetes mellitus diagnosed 6 months ago; he was prescribed metformin by his previous physician but stopped taking it due to diarrhea.  He was unable to follow up with the physician and has not taken any other medications.  The patient exercises regularly and follows a low-carbohydrate diet.  Laboratory results show a fasting blood glucose of 140 mg/dL and a hemoglobin A1c of 7.5%.  The physician counsels the patient about adding canagliflozin to optimize glycemic control.  Which of the following tests should be ordered prior to initiating this new medication?

A 21-year-old man comes to the emergency department due to several days of dizziness and extreme fatigue.  The patient has been drinking a lot of water and urinating more than usual for the past 2 weeks.  He developed nausea and vomiting one day ago and has had difficulty keeping food and liquids down.  The patient has no other medical conditions and takes no medications.  Blood pressure is 90/60 mm Hg, pulse is 120/min, and respirations are 20/min.  Urinalysis is positive for glucose and ketones.  The patient is given intravenous fluids and an intravenous infusion of recombinant human insulin without any structural modifications.  His condition improves, and he remains stable for the rest of the hospitalization.  In preparation for discharge, a plan is made to prescribe a regimen that includes a subcutaneous formulation of the same insulin that the patient was receiving intravenously.  Which of the following drug concentration curves shown in the image below is most likely to be obtained after subcutaneous injection of this insulin?

A 32-year-old previously healthy woman comes to the office due to several weeks of anxiety, palpitations, excessive sweating, and thinning hair.  The symptoms have progressively worsened and interfered significantly with her daily activities.  The patient does not use tobacco, alcohol, or illicit drugs.  Blood pressure is 130/70 mm Hg and pulse is 104/min.  On physical examination, there is lid lag, moderate exophthalmos, and fine tremors of the outstretched hands.  After the diagnosis is made, she is prescribed propranolol for immediate symptom control.  Which of the following findings is most likely to persist in this patient despite this therapy?

A 52-year-old, post-menopausal woman comes to the office for a follow-up appointment.  Six months ago, the patient was evaluated for recurrent, brief episodes of excessive warmth and sweating, which were interfering with her usual activities.  Thyroid hormone levels were normal, and the patient was subsequently diagnosed with menopausal hot flashes.  Treatment with estrogen-containing hormone replacement therapy was begun with significant symptom improvement.  She has no other medical conditions and takes no other medications.  Which of the following most likely occurred in this patient as a result of her medication use?

A 60-year-old man comes to the office for follow-up of type 2 diabetes mellitus.  His treatment regimen includes oral medications and a once-daily injection of long-acting subcutaneous insulin.  The patient is adherent with treatment and has modified his lifestyle.  Review of home glucose measurements shows that his postprandial glucose levels are frequently elevated; however, fasting levels are normal.  He has no other medical conditions and does not use tobacco, alcohol, or recreational drugs.  Vital signs are within normal limits.  Physical examination shows no abnormalities.  Hemoglobin A1c is 8.3%.  Additional insulin therapy 3 times a day before each meal is planned to improve glycemic control.  Which of the following types of insulin is most appropriate for this patient?

A 48-year-old woman comes to the emergency department due to back pain after minor trauma.  She has no leg weakness or numbness.  Review of systems is positive for recent-onset hot flashes and irregular menses; her most recent menstruation was 2 weeks ago.  The patient has a long history of hypothyroidism treated with levothyroxine and rheumatoid arthritis treated with methotrexate.  She has also taken oral prednisone for frequent symptom flares.  The patient does not use tobacco, alcohol, or illicit drugs, and she consumes a balanced diet.  Physical examination shows point tenderness over the midthoracic spine.  The straight-leg raising test is negative, and neurologic examination of the lower extremities shows no abnormalities.  Spine imaging is shown below:

Which of the following contributed most to this patient’s current condition?

A 52-year-old woman comes to the office for follow-up of type 2 diabetes mellitus.  The patient was diagnosed with diabetes 6 months ago and initiated intensive lifestyle modification with increased exercise and a calorie-restricted diet; since that time, she has felt better subjectively but has lost only 2 kg (4.4 lb).  Vital signs are normal.  BMI is 35 kg/m².  Fasting glucose is 155 mg/dL and hemoglobin A1c is 8.0%.  Serum renal and liver function markers are normal.  After discussion with the patient, metformin therapy is initiated.  Which of the following physiologic changes are most likely to result as a direct effect of this medication?