Antimicrobials — MCQs

A 60-year-old man comes to the physician because of a 2-day history of blood in his urine, lower abdominal pain, and a burning sensation while micturating. Five months ago, he was diagnosed with high-grade non-Hodgkin lymphoma and a deep vein thrombosis of his right popliteal vein. His medications include polychemotherapy every 3 weeks and a daily subcutaneous dose of low molecular weight heparin. The last cycle of chemotherapy was 2 weeks ago. His temperature is 37°C (98.6°F), pulse is 94/min, and blood pressure is 110/76 mm Hg. Examination shows bilateral axillary and inguinal lymphadenopathy, hepatosplenomegaly, and mild suprapubic tenderness. Laboratory studies show: Hemoglobin 10.2 g/dL Leukocytes 4,300/mm3 Platelet count 145,000/mm3 Partial thromboplastin time 55 seconds Prothrombin time 11 seconds (INR=1) Urine RBCs 50–55/hpf RBC casts negative WBCs 7/hpf Epithelial cells 5/hpf Bacteria occasional Administration of which of the following is most likely to have prevented this patient's current condition?

A 45-year-old woman presents to the office complaining of fatigue and unintentional weight loss. On examination, there is a palpable firm lymph node in the cervical area. Biopsy of the lymph node reveals Hodgkin’s lymphoma. The patient agrees to start the standard chemotherapy regimen. A few months later, after the completion of 3 successful courses, the patient presents with a dry cough and progressively worsening shortness of breath. Her temperature is 37°C (98.6°F), the blood pressure is 110/70 mm Hg, the pulse is 72/min, and the respirations are 16/min. Pulse oximetry shows an O2 saturation of 94% on room air. On spirometry, the patient's FEV1/FVC ratio is normal. Chest CT reveals bilateral diffuse cystic airspaces in middle and lower lung fields. Which of the following is the most likely cause of this patient’s current symptoms?

A 65-year-old man comes to the physician for a routine health maintenance examination. He feels well. His most recent examination 2 years ago included purified protein derivative (PPD) skin testing and showed no abnormalities. He is a retired physician and recently came back from rural China where he completed a voluntary service at a local healthcare center. A PPD skin test is performed. Three days later, an induration of 12 mm is noted. An x-ray of the chest shows no abnormalities. He is started on a drug that inhibits the synthesis of mycolic acid. This patient is at greatest risk of developing which of the following adverse effects?

A 25-year-old woman is brought to the emergency department because of a 1-day history of lower abdominal pain and vaginal bleeding. Her last menstrual period was 7 weeks ago. A urine pregnancy test is positive. A pelvic ultrasound shows a normal appearing uterus with an empty intrauterine cavity and a minimal amount of free pelvic fluid. Treatment with a drug is begun. Which of the following is the most likely effect of this drug?

A 34-year-old male comes to his family physician with complaints of joint pain that has been present for over 7 weeks. Prior to the onset of his arthritis, he recalls having a gastrointestinal infection which caused mild diarrhea and abdominal cramps. He recovered well and had no issues until his joint pain started. A prescription for naproxen was previously prescribed but he still does not feel well. He has no significant past medical or family history. On physical examination, his blood pressure is 120/78 mm Hg, respirations are 17/min, pulse is 64/min, and temperature is 36.7°C (98.0°F). Which of the following therapies is likely to be most beneficial in treating this patient’s condition?

A 35-year-old man comes to the physician because of a 4-month history of intermittent headaches. They have been getting progressively worse and no longer respond to ibuprofen. He also complains of weight gain and excessive sweating. Physical examination shows prominent supraorbital ridges, prognathism, macroglossia with thick lips, and disproportionately broad hands and feet. There is decreased peripheral vision bilaterally on visual field testing. An MRI of the brain shows a mass in the sella turcica. Genetic analysis of a biopsy specimen from the mass shows cells that overexpress adenylyl cyclase. Which of the following is the most appropriate pharmacotherapy for this condition?

A 32-year-old man presents to the clinic for follow up for treatment of latent tuberculosis. He is a healthcare worker and began isoniazid 3 months ago after a routine PPD yielded a 12-mm induration. He feels otherwise well and attributes this to his vegetarian diet that he has been following for the past 4 years. His past medical history is unremarkable, but his family history is significant for a "liver disease," the specifics of which are unknown. Physical exam shows mildly reduced sensation to pinprick over the distal lower extremities. The abdomen is soft, nontender, and without hepatosplenomegaly. Laboratory studies demonstrate the following: Serum: Hemoglobin: 9.6 g/dL Hematocrit: 34% Leukocyte count: 9,200/mm^3 with normal differential Platelets: 270,000/mm^3 Mean corpuscular volume: 77 µm^3 AST: 92 U/L ALT: 84 U/L Ferritin: 302 ng/mL (normal 15-200 ng/mL) Total iron: 273 µg/dL (normal 50-170 µg/dL) TIBC: 150 µg/dL (normal 250–370 µg/dL) Which of the following is the most appropriate next step in management?

A 25-year-old college student is diagnosed with acute myelogenous leukemia after presenting with a 3-week history of fever, malaise, and fatigue. He has a history of type 1 diabetes mellitus, multiple middle ear infections as a child, and infectious mononucleosis in high school. He currently smokes 1 pack of cigarettes per day, drinks a glass of wine per day, and denies any illicit drug use. The vital signs include: temperature 36.7°C (98.0°F), blood pressure 126/74 mm Hg, heart rate 87/min, and respiratory rate 17/min. On physical examination, his pulses are bounding; his complexion is pale, but breath sounds remain clear. A rapidly progressive form of leukemia is identified, and the patient is scheduled to start intravenous chemotherapy. Which of the following treatments should be given to this patient to prevent or decrease the likelihood of developing acute renal failure during treatment?

A 9-year-old boy is brought to the emergency department by his parents after a 2-day history of fever, productive cough, and severe dyspnea. The parents report that the boy had no health problems at birth but developed respiratory problems as an infant that have continued throughout his life, including recurrent pulmonary infections. Vital signs include: temperature of 37.5ºC (99.5ºF), pulse of 105/min, respiratory rate of 34/min, and SpO2 of 87%. Physical examination shows digital clubbing and cyanosis. Chest X-rays show hyperinflation of the lungs and chronic interstitial changes. The boy’s FEV1/FVC ratio is decreased, and his FRC is increased. The resident reviewing his case is studying new gene therapies for this boy’s condition that will reintroduce the gene for which this boy is defective. An important component of this therapy is identifying a vector for the selective introduction of the replacement gene into the human body. Which of the following would be the best vector to provide gene therapy for this boy’s respiratory symptoms?

A 45-year-old man is brought to the emergency department 20 minutes after being rescued from a fire in his apartment complex. He thinks he might have briefly lost consciousness while he was trapped in a smoke-filled room before firefighters were able to free him 20 minutes later. He reports headache, dizziness, and occasional cough. He has no difficulty breathing, speaking, or swallowing. He appears mildly uncomfortable and agitated. His temperature is 36.4°C (97.5°F), pulse is 90/min, respirations are 16/min, and blood pressure is 155/68 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 92%. Breath sounds are coarse. The remainder of the examination shows no abnormalities. Arterial blood gas analysis on room air shows : pH 7.30 PCO2 38 mm Hg PO2 70 mm Hg HCO3- 18 mEq/L COHb 2% (N < 3) In addition to oxygen supplementation with a non-rebreather mask, which of the following is the most appropriate next step in management?