All practice questions

Match each clinical intervention (left) with the underlying pharmacokinetic or pharmacodynamic mechanism (right) responsible for the resulting drug interaction or therapeutic effect.

A 38-year-old man with a history of advanced human immunodeficiency virus infection is evaluated in the infectious disease clinic for a two-week history of worsening blurred vision and "floating spots" in his right eye. His current CD4+ T-cell count is 32 cells/mm³. Vital signs show a temperature of 37.1°C (98.8°F), blood pressure of 118/76 mmHg, and heart rate of 78/min. Funduscopic examination reveals extensive yellow-white retinal infiltrates with associated perivascular hemorrhage. He is immediately initiated on intravenous ganciclovir therapy. After three weeks of compliant treatment, serial examinations indicate continued progression of the retinal lesions. Subsequent genotypic resistance testing of the responsible pathogen identifies a significant mutation in the UL97 gene. Which of the following best describes the direct molecular consequence of this specific genetic alteration?

A 55-year-old man presents to the emergency department with a 4-day history of high fever, productive cough with rust-colored sputum, and right-sided pleuritic chest pain. Vital signs are temperature 38.9°C (102°F), blood pressure 120/80 mmHg, heart rate 110/min, and respiratory rate 24/min. Based on the highly suspected diagnosis of lobar consolidation secondary to bacterial pneumonia, which of the following physical examination findings are classically expected over the right lower lung field? (Select all that apply)

A 58-year-old woman with a history of recurrent nephrolithiasis and severe osteoporosis is evaluated in the clinic. Laboratory studies show a serum calcium of 11.2 mg/dL, serum phosphorus of 2.1 mg/dL, and an intact parathyroid hormone level of 145 pg/mL (normal: 10-65 pg/mL). The physician explains that her hypophosphatemia is a direct result of the elevated hormone acting on the renal proximal tubules. Arrange the following cellular and molecular events in the correct chronological sequence by which this hormone decreases renal phosphate reabsorption.

A 52-year-old woman with a history of a deceased-donor renal transplant 3 years ago presents to the clinic with fever, productive cough, and shortness of breath. She is maintained on a stable immunosuppressive regimen of tacrolimus and mycophenolate mofetil. Her blood pressure is 128/78 mmHg and pulse is 88/min. Laboratory tests show a serum creatinine of 1.1 mg/dL, which is unchanged from her baseline over the past year. She is diagnosed with community-acquired pneumonia, and oral clarithromycin is added to her regimen. If the physician were to leave the tacrolimus dose unchanged, which of the following best describes the anticipated changes in the pharmacokinetic parameters of tacrolimus?

During a pre-pregnancy counseling evaluation, a 29-year-old nulliparous woman is noted to have an abnormal oxygen saturation profile. She reports a long-standing history of becoming easily winded during moderate physical exertion, which she previously attributed to being out of shape. She has no history of syncope or chest pain. Vital signs show a blood pressure of 112/68 mmHg and a heart rate of 84/min. Pulse oximetry reveals an oxygen saturation of 99% in her right index finger and 86% in her right great toe. Physical examination is notable for a palpable impulse along the left sternal border. Auscultation reveals a loud, palpable second heart sound and a harsh holosystolic murmur at the left lower sternal border that increases in intensity with inspiration. Inspection of her extremities demonstrates significant clubbing of the toes bilaterally, while her fingernails appear entirely normal with no clubbing or cyanosis. Which of the following is the most likely anatomic mechanism underlying this patient's specific extremity findings?

A 34-year-old man is brought to the emergency department in a resource-limited setting with severe agitation, hypersalivation, and extreme panic upon attempting to drink water. His wife reports that he was bitten on the right calf by a feral dog approximately six weeks ago, but he did not seek medical evaluation at the time. He is admitted to the intensive care unit but rapidly deteriorates and expires on hospital day 3.

Arrange the pathophysiologic events of this patient's infectious process in the correct chronological order, beginning from the initial inoculation to the eventual capacity for transmission.

Match each detailed neuro-ophthalmologic physical examination finding to its corresponding underlying anatomic lesion or pathophysiological mechanism.

A 42-year-old woman is brought to the emergency department complaining of sudden-onset, severe shortness of breath and progressive lightheadedness over the past 2 hours. She has a history of stage IV breast cancer and is currently undergoing chemotherapy. Her temperature is 37.1 C (98.8 F), blood pressure is 82/50 mm Hg, heart rate is 122/min, and respiratory rate is 26/min. Pulse oximetry is 94% on room air. Her extremities are cool and clammy. Which of the following physical examination findings are most likely to be present in this patient? (Select all that apply)

A $38$-year-old woman is evaluated in the emergency department for the sudden onset of severe dyspnea and right-sided pleuritic chest pain. She has a history of systemic lupus erythematosus and has experienced two prior first-trimester miscarriages. She currently takes hydroxychloroquine. Her temperature is $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), blood pressure is $108/64\text{ mmHg}$, pulse is $118/\text{min}$, and respirations are $26/\text{min}$. Pulse oximetry shows $92\%$ on room air. Physical examination reveals clear breath sounds bilaterally. Cardiac examination demonstrates a regular, tachycardic rhythm with a palpable impulse along the left parasternal border. Auscultation reveals a widely split second heart sound with a loud pulmonic component. A high-pitched, blowing holosystolic murmur is heard best at the left lower sternal border. When the patient takes a deep breath in, the intensity of this holosystolic murmur significantly increases. Examination of the lower extremities shows asymmetric right calf swelling with trace pitting edema. Which of the following is the most likely explanation for the auscultatory finding that increases with deep inspiration in this patient?

A 55-year-old man presents to the outpatient continuity clinic with a 4-day history of lower back pain. He describes the pain as a dull ache in the lumbar region that started gradually. He works as an accountant and denies any recent falls or major trauma. The physician conducts a comprehensive medical history evaluation to determine the appropriate diagnostic and management plan. Which of the following historical findings, if reported by the patient, would be considered 'red flag' symptoms that correctly prompt urgent diagnostic imaging? (Select all that apply)

A $42$-year-old man is admitted to the hospital with sudden-onset right-sided pleuritic chest pain and shortness of breath. He has a $2$-month history of significant lower extremity edema and was recently diagnosed with primary membranous nephropathy. His temperature is $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), blood pressure is $138/86\text{ mmHg}$, pulse is $112/\text{min}$, and respirations are $22/\text{min}$. Pulse oximetry shows $91\%$ on room air. Computed tomography angiography of the chest confirms a right lower lobe segmental pulmonary embolism. The patient is administered a standard weight-based intravenous bolus of unfractionated heparin, followed by a continuous infusion. Over the next $24$ hours, the infusion rate is increased $3$ times according to a high-dose nomogram; however, the patient's activated partial thromboplastin time (aPTT) remains subtherapeutic at $32$ seconds (baseline $30$ seconds; therapeutic target $60$-$80$ seconds). Which of the following is the most likely underlying mechanism for this patient's subtherapeutic laboratory response?

A $68$-year-old woman is evaluated in the cardiology clinic for symptomatic palpitations. She has a history of ischemic cardiomyopathy, heart failure with reduced ejection fraction, and chronic atrial fibrillation. Her current daily medications include lisinopril, metoprolol succinate, furosemide, and digoxin. Her vital signs are stable, but an electrocardiogram reveals frequent premature ventricular contractions and runs of non-sustained ventricular tachycardia. The physician decides to initiate oral amiodarone therapy. Recognizing a critical drug-drug interaction, the physician simultaneously reduces the patient's digoxin dose by $50\%$. This empiric dose reduction is primarily required to compensate for which of the following amiodarone-induced pharmacokinetic changes?

The accurate evaluation of a patient's medical history, particularly regarding recent pharmacological interventions, is critical in identifying the etiology of acute clinical deteriorations. You are evaluating five patients presenting with acute, severe complications. Match each patient's clinical profile with the specific targeted historical inquiry (offending agent) that must be identified to establish the mechanism of their acute deterioration.

Match the following classic cardiovascular physical examination findings with their primary underlying pathophysiologic mechanism.

A 64-year-old man is brought to the outpatient clinic by his daughter due to worsening confusion, inverted sleep-wake cycles, and forgetfulness over the past week. His medical history is notable for compensated cirrhosis secondary to chronic hepatitis C viral infection. His vital signs are within normal limits. During the physical examination, the physician asks the patient to extend his arms forward with his wrists dorsiflexed and fingers spread apart. After a few seconds, the patient exhibits brief, rapid, arrhythmic, downward lapses of both hands, followed by a quick return to the original extended position. Which of the following is the most accurate clinical interpretation of this specific physical examination finding?

Match each clinical vignette with the molecular mechanism of the primary virulence factor responsible for the patient's symptoms.

A 75-year-old retired teacher comes to the primary care clinic reporting an episode of lightheadedness that resulted in a brief loss of consciousness while climbing stairs at his home. He reports no chest pain, palpitations, or shortness of breath at rest. His vital signs are within normal limits. Cardiac auscultation reveals a harsh, late-peaking systolic crescendo-decrescendo murmur at the right second intercostal space that radiates to the carotid arteries. Based on the most likely underlying diagnosis, which of the following peripheral pulse abnormalities is characteristically found on physical examination of this patient?

Evaluate the following distinct patient historical profiles. Match each patient's specific travel and environmental exposure history to the most likely corresponding infectious disease diagnosis.

A 28-year-old woman presents to the emergency department with a 1-day history of sharp, right-sided chest pain that worsens with deep inspiration. She has no cough, hemoptysis, or shortness of breath. Her past medical history is significant for mild asthma, for which she uses an albuterol inhaler as needed. She also takes a combined oral contraceptive pill. She has not had any recent surgeries, and she has not traveled recently. Temperature is 37.1°C (98.8°F), blood pressure is 118/76 mm Hg, pulse is 92/min, and respirations are 16/min. Pulse oximetry is 98% on room air. Physical examination reveals clear lungs bilaterally and a regular heart rhythm without murmurs. There is no calf swelling, tenderness, or erythema. Which of the following is the most appropriate next step in diagnostic evaluation?