A 64-year-old woman comes to the hospital due to sudden-onset right arm weakness and difficulty speaking, which completely resolved within 20 minutes.  The patient has had no shaking movements, headache, nausea, photophobia, or anxiety.  She has a history of hypertension and hypercholesterolemia and takes amlodipine and rosuvastatin, respectively.  Her blood pressure is 125/70 mm Hg and pulse is 78/min and regular.  Neurologic examination is unremarkable.  Fingerstick glucose is within normal limits.  ECG shows normal sinus rhythm.  Carotid Doppler reveals mild left common carotid artery stenosis.  MRI of the brain and echocardiogram are unremarkable.  If the patient is started on an additional medication that is indicated for her condition, which of the following adverse effects is most likely to occur?

A 35-year-old man with a known history of peptic ulcer disease comes to the physician with sudden onset of pain, swelling, and redness at the base of his great toe.  The patient was awakened in the middle of the night by the pain and was unable to go back to sleep.  He has no history of trauma to the joint.  Physical examination shows swelling, erythema, and exquisite tenderness involving the right first metatarsophalangeal joint.  Fine-needle aspiration of the joint shows needle-shaped, negatively birefringent crystals.  After making the diagnosis, the physician prescribes an appropriate medication.  Shortly after starting the medication, the patient develops nausea, vomiting, and diarrhea.  Which of the following is the most likely mechanism of action of the drug prescribed to this patient?

A 55-year-old nurse was started on multidrug therapy 3 weeks ago to treat pulmonary tuberculosis contracted from a former patient.  He comes to his primary care provider due to fatigue and low-grade fever for several days.  He also has had muscle aches and severe joint pain in his elbows, wrists, and knees.  The patient says, “I don’t think it’s the flu; I had the vaccine months ago.”  He has no current respiratory symptoms apart from pleuritic chest pain.  The patient has no other significant past medical or family history.  His examination is unremarkable. Laboratory results are as follows:

An abnormality in which of the following metabolic processes most likely underlies this patient’s current condition?

A 56-year-old man comes to the urgent care center with severe knee pain.  He was feeling well until he awoke this morning with acute pain, redness, and swelling in the knee.  The patient does not smoke but did drink heavily at a wedding reception the night before.  Past medical history is notable for recent peptic ulcer disease.  He is treated with oral colchicine and experiences significant relief of symptoms within 12 hours.  The drug used in this patient most likely affects which of the steps shown in the diagram below?

A 55-year-old woman comes for evaluation of persistent morning stiffness.  She was diagnosed with rheumatoid arthritis 4 months ago and was prescribed methotrexate.  The patient currently takes the maximum tolerated dose, along with folic acid and as-needed naproxen.  Vital signs are normal.  On examination, swelling, tenderness, and pain on range of motion are found at the metacarpophalangeal and proximal interphalangeal joints and wrists bilaterally.  Treatment with etanercept is considered.  Which of the following tests should be performed before beginning treatment with this agent?

A 34-year-old woman comes to the physician for a follow-up visit.  She was diagnosed with rheumatoid arthritis 3 months ago and started on methotrexate therapy.  Despite treatment, she continues to have several hours of morning stiffness daily and frequently awakens at night due to joint pain.  Physical examination shows swelling and tenderness in the joints of her hands and wrists.  Etanercept is subsequently added to her treatment regimen.  This medication is best characterized as which of the following?

A 54-year-old man comes to the office due to severe foot pain.  The patient attended a wedding reception where he drank several alcoholic beverages, then woke the following morning with pain.  He has a long history of gouty arthritis, and his current symptoms are similar to previous flares of the disease.  Past medical history includes type 2 diabetes mellitus and recently diagnosed peptic ulcer disease.  Physical examination shows erythema, warmth, and swelling at the left first metatarsophalangeal joint.  The patient is started on a new medication for gout that provides significant relief of his symptoms, but he returns to the clinic a week later with diarrhea and persistent nausea.  The drug used in this patient most likely affects which of the following cell structures?

A 45-year-old woman comes to the office for follow-up of arthritis.  For the last year, she has had fatigue, weight loss, and progressive joint pain in the hands associated with prolonged morning stiffness.  Past medical history includes hypothyroidism, for which she takes levothyroxine.  The patient does not use tobacco or alcohol.  Examination shows doughy swelling involving multiple metacarpophalangeal joints in both hands.  Following initial diagnostic testing, a multidrug treatment regimen is started.  Soon after treatment begins, she develops painful mouth ulcers and nausea.  Liver function tests show new aspartate transaminase and alanine transaminase elevations.  Which of the following medications is most likely responsible for the adverse effects seen in this patient?

A 55-year-old man comes to the emergency department with severe right foot pain that started suddenly in the middle of the night.  He has never had such symptoms before.  The patient has a history of diet-controlled type 2 diabetes mellitus.  BMI is 32 kg/m².  Physical examination shows swelling and tenderness of the first metatarsophalangeal joint.  Leukocyte count is 13,500/mm³ and serum creatinine is 0.8 mg/dL.  Joint aspiration is performed, and synovial fluid microscopic findings are shown in the image below:

Which of the following is the best initial treatment for this patient?

A 48-year-old man comes to the office due to several hours of severe right knee pain.  The patient has a history of peptic ulcer disease and gastroesophageal reflux disease.  His right knee is swollen, erythematous, and tender.  Arthrocentesis is performed and synovial fluid analysis shows needle-shaped, negatively birefringent crystals with many neutrophils.  The medication given to this patient selectively binds to an interleukin-1 inducible enzyme that is highly expressed by inflammatory cells and undetectable in the surrounding normal tissue.  Which of the following is most likely the drug used in this patient’s treatment?

A 61-year-old man comes to the office to follow up acute arthritis.  He was seen at a nearby urgent care center 6 weeks ago for sudden-onset pain and swelling in the ankle.  The patient was treated with an unknown analgesic with rapid relief of his pain.  Since that time, his pain has resolved completely and he is now feeling well.  Past medical history is notable for hypercholesterolemia, for which he takes atorvastatin.  He also has a history of recurrent renal colic.  On examination, his ankle appears normal with no redness, warmth, or swelling.  Serum uric acid level is 9.8 mg/dL.  Which of the following is the best agent for long-term management of this patient?

A 45-year-old woman comes to the office due to gradually progressive pain, stiffness, and swelling of her hand joints for the past several months.  The patient has had prolonged morning stiffness and significant restriction of her daily activities due to the pain, as well as generalized fatigue.  She describes the symptoms over the last several weeks as “disabling,” and she needs assistance with activities of daily living in the morning.  The patient has tried over-the-counter pain medications, such as acetaminophen and ibuprofen, with only minimal relief of her symptoms.  She has no other medical problems.  Family history is significant for diabetes mellitus on her maternal side.  Which of the following drugs would provide the most rapid relief of her symptoms?

A 65-year-old woman comes to the office to discuss the results of a recent screening bone density test.  She is generally healthy, eats a balanced diet, and gets regular weight-bearing exercise.  The patient does not smoke and drinks alcohol only occasionally.  BMI is 20 kg/m².  Physical examination is unremarkable.  The DXA scan results reveal osteoporosis, with a T-score of −2.7 at the lumbar spine and −2.3 at the right hip.  Treatment with oral risedronate is prescribed.  This medication is most likely to improve this patient’s current condition through which of the following mechanisms?

A 58-year-old woman comes to the office with left knee pain.  The pain began a year ago and has progressively become more severe.  The pain is worse later in the day and is now limiting her normal day-to-day activities.  She has no history of injury to the joint and has no significant pain in any other joints.  The patient has attempted treatment with acetaminophen, but that has not provided adequate relief.  She does not use tobacco, alcohol, or illicit drugs and works as a school bus driver.  Her BMI is 34 kg/m².  Left knee joint examination shows a mild effusion, crepitus on movement, and joint line tenderness.  The patient is started on celecoxib therapy.  The presence of which of the following conditions in this patient’s medical history would make this medication the preferred treatment?

A 36-year-old man is evaluated due to swelling and severe pain of the right foot.  Medical history is significant for kidney transplant due to focal segmental glomerulosclerosis.  The patient is diagnosed with gout and treated with prednisone.  Six weeks later, the patient is seen at follow-up.  He has no foot pain and the swelling has subsided.  Serum uric acid level is 13.5 mg/dL and creatinine level is 0.9 mg/dL.  Allopurinol is prescribed.  Initiation of this drug would most likely increase the activity of which of the following medications?

A 75-year-old man comes to the urgent care center with acute onset of a pruritic rash after eating strawberries.  The patient has no associated swelling in or around the mouth, no wheezing, and no difficulty breathing.  Past medical history is notable for coronary artery disease, for which he takes atorvastatin, lisinopril, aspirin, and metoprolol.  He also has a history of allergy to dog and cat dander.  The patient does not use alcohol or tobacco.  His family reports that he lives alone and his functional status has been declining.  He walks with a cane, has poor vision, and is frequently forgetful.  The patient also has occasional dizziness when standing up and a history of frequent falls.  Which of the following would be the most appropriate medication to treat this patient’s acute symptoms?

A 52-year-old man comes to the office for an annual preventive visit.  He has a history of seasonal allergies, and has recently started taking a medication that has improved his runny nose, sneezing, and watery eyes.  Medical history is remarkable for diet-controlled type 2 diabetes mellitus and eczema.  He is not on any other medications.  He does not use tobacco, alcohol, or illicit drugs.  Examination shows a well-appearing man with flushed cheeks and dilated pupils.  This patient’s physical examination findings are best explained by which of the following mechanisms?

A 48-year-old woman enrolls in a clinical trial.  The patient has had persistent discomfort in her lower extremities for the past 2 years.  She describes an uncomfortable sensation in her legs, particularly in the evening and at night, but no pain.  The symptoms are relieved with leg movement or walking.  She has experienced no behavioral or mood changes.  The patient intermittently experiences mild migraines, and during a recent episode she found that antiemetic therapy worsened the leg discomfort.  Vital signs are normal, and physical examination shows no abnormalities.  Blood cell counts, serum chemistry studies, and serum iron levels are within normal limits.  Treatment with a novel agent, an alpha-2-delta calcium channel ligand, is initiated.  The patient receives significant symptom relief with this therapy.  The novel agent used in this trial is most similar to which of the following medications?

A 10-year-old boy with a history of mild, persistent asthma is brought to the office for follow-up.  His asthma symptoms are controlled with an inhaled beta-agonist and inhaled glucocorticoid therapy.  There is no family history of asthma, but both his parents and older brother have short stature.  The patient’s mother is concerned about the use of glucocorticoids because she read on the Internet that they cause growth retardation.  The patient’s glucocorticoid medication is stopped, and he is started on a trial of inhaled cromolyn.  Which of the following is the most likely site of action of this new medication?

A 65-year-old woman comes to the office to discuss pain at the posterior chest wall.  She was seen 4 months ago for acute shingles involving a right mid-thoracic dermatome.  The patient was not treated at that time because she had a delayed presentation and the lesions were already well-crusted and healing.  The skin lesions subsequently cleared completely.  However, since then, she has had persistent burning and stabbing pain in the same region that has now become severe.  She has tried oral acetaminophen without relief.  During discussion of treatment options, the patient says she does not want any systemic medications due to concerns about possible side effects.  She is started on topical capsaicin cream, and her pain improves markedly over the next several days.  Decreased activity of which of the following neurotransmitters is most likely associated with pain relief in this patient?