Antimicrobials — MCQs

A 60-year-old female presents to her gynecologist with bloating, abdominal discomfort, and fatigue. She has a history of hypertension and takes hydrochlorothiazide. Physical exam reveals ascites and right adnexal tenderness. Initial imaging reveals a mass in the right ovary and eventual biopsy of the mass reveals ovarian serous cystadenocarcinoma. She is started on a chemotherapeutic agent with plans for surgical resection. Soon after starting the medication, she develops dysuria and hematuria. Laboratory analysis of her urine is notable for the presence of a cytotoxic metabolite. Which of the following mechanisms of action is consistent with the medication in question?

A 71-year-old man with asthma and dementia presents to the emergency department in acute respiratory distress. He is with his home care nurse who explains that he has been hiding his bronchodilators for the past 3 weeks, and she has had to dutifully look for them and help him administer them. Over the past 2 days, however, she has been completely unsuccessful in finding his medication and was in the process of contacting his primary care physician for a refill of his prescription when he suddenly had a ‘coughing fit’ and began wheezing uncontrollably. The patient is obviously uncomfortable and is using accessory muscles of respiration to catch his breath. He is struggling to speak and is immediately given multiple doses of nebulized albuterol and intravenous methylprednisolone; however, his condition does not improve. The arterial blood gas test result shows pH 7.20. He is subsequently intubated and sent to the intensive care unit (ICU). In patients who are intubated for mechanical ventilation, there is an increased risk for ventilator-associated pneumonia. Which of the following should be prophylactically given to this patient to lower his risk for pneumonia?

A 52-year-old man presents to his primary care physician because he has been experiencing shortness of breath and cough. He began feeling short of breath when playing recreational soccer with his friends. Over time these episodes have become more severe. They now impair his ability to work as a construction worker. In addition, he has developed a chronic dry cough that has been increasing in intensity. Radiography reveals subpleural cystic enlargement, and biopsy reveals fibroblast proliferation in the affected tissues. Which of the following describes the mechanism of action for a drug that can cause a similar pattern of pulmonary function testing as would be seen in this disease?

A 64-year-old woman comes to the physician because of a 7-month history of abdominal discomfort, fatigue, and a 6.8-kg (15-lb) weight loss. Physical examination shows generalized pallor and splenomegaly. Laboratory studies show anemia with pronounced leukocytosis and thrombocytosis. Cytogenetic analysis shows a BCR-ABL fusion gene. A drug with which of the following mechanisms of action is most appropriate for this patient?

An 18-month-old boy is brought to the physician because of walking difficulties. His mother says that he cannot walk unless he is supported. She has also noted orange, sandy residues in his diapers. Over the past year, she has frequently caught him pulling his toenails and chewing the tips of his fingers. Examination shows scarring of his fingertips. Muscle tone is decreased in the upper and lower extremities. He cannot pick up and hold small objects between the tips of the index finger and the thumb. The most appropriate pharmacotherapy for this patient's condition inhibits which of the following conversions?

A 60-year-old man is rushed to the emergency room after he was found unconscious in bed that afternoon. The patient’s wife says he has been confused and irritable for the past several days. She says he has a history of chronic daily alcohol abuse and has been hospitalized multiple times with similar symptoms His temperature is 37°C (98.6°F), the blood pressure is 110/80 mm Hg, the pulse is 90/min, and the respiratory rate is 14/min. On physical examination, the patient is minimally responsive to painful stimuli. His abdomen is distended with positive shifting dullness. Laboratory results are as follows: Complete blood count Hematocrit 35% Platelets 100,000/mm3 White blood cells 5000/mm3 Liver function studies Serum Albumin 2 g/dL Alkaline phosphatase (ALP) 200 IU/L Aspartate aminotransferase (AST) 106 IU/L Alanine aminotransferase (ALT) 56 IU/L The patient is admitted to the hospital and started on the appropriate treatment to improve his mental status. Which of the following best describes the mechanism of action of the drug that is most likely used to treat this patient’s symptoms?

A 25-year-old man presents with abdominal pain and bloody diarrhea. His symptoms have been recurrent for the past few months, and, currently, he says he is having on average four bowel movements daily, often bloody. He describes the pain as cramping and localized to the left side of his abdomen. He also says that he has lost around 4.5 kg (10 lb) over the past 3 months. There is no other significant past medical history and the patient is not on current medications. His temperature is 37.7° C (100.0° F), pulse rate is 100/min, respiratory rate is 18/min, and blood pressure is 123/85 mm Hg. On physical examination, there is mild tenderness to palpation in the lower left quadrant of the abdomen with no rebound or guarding. Laboratory studies show anemia and thrombocytosis. Colonoscopy is performed, which confirms the diagnosis of ulcerative colitis (UC). What is the mechanism of action of the recommended first-line medication for the treatment of this patient’s condition?

A 46-year-old male presents to his dermatologist for routine follow-up of his psoriasis. He was last seen in the office six months prior, at which time he started undergoing ultraviolet light therapy. He reports that he initially noticed an improvement in his symptoms but the effects were transient. He has also started noticing pain and stiffness in his fingers. His past medical history is notable for obesity and diabetes mellitus. He takes metformin. His temperature is 99°F (37.2°C), blood pressure is 130/80 mmHg, pulse is 80/min, and respirations are 16/min. Multiple plaques with scaling are noted on the extensor surfaces of the upper and lower extremities. The patient’s physician suggests stopping the ultraviolet light therapy and starting an injectable medication that acts as a decoy receptor for a pro-inflammatory cytokine. Which of the following is an adverse effect associated with the use of this medication?

An 8-year-old boy is brought to the emergency department by his parents because of sudden onset of abdominal pain beginning an hour ago. The parents report that their son has also had an episode of dark urine earlier that morning. Three days ago, he was diagnosed with a urinary tract infection and was treated with trimethoprim-sulfamethoxazole. He emigrated from Liberia to the US with his family 3 years ago. There is no personal history of serious illness. His immunizations are up-to-date. Vital signs are within normal limits. Examination shows diffuse abdominal tenderness and scleral icterus. The spleen is palpated 1–2 cm below the left costal margin. Laboratory studies show: Hemoglobin 10 g/dL Mean corpuscular volume 90 μm3 Reticulocyte count 3% Serum Bilirubin Total 3 mg/dL Direct 0.5 mg/dL Haptoglobin 20 mg/dL (N=41–165 mg/dL) Lactate dehydrogenase 160 U/L Urine Blood 3+ Protein 1+ RBC 2–3/hpf WBC 2–3/hpf Which of the following is the most likely underlying cause of this patient's symptoms?

A 45-year-old male presents to his primary care doctor complaining of abdominal pain. He reports a three-month history of intermittent burning pain localized to the epigastrium that worsens 2-3 hours after a meal. He attributes this pain to increased stress at his job. He is otherwise healthy and takes no medications. He does not smoke or drink alcohol. His temperature is 98.8°F (37.1°C), blood pressure is 130/85 mmHg, pulse is 90/min, and respirations are 18/min. Physical examination reveals mild epigastric tenderness to palpation. A urease breath test is positive. Which of the following treatments is most appropriate first-line therapy for this patient?