Antimicrobials — MCQs

A 21-year-old man presents to the physician with complaint of fever and non-bloody diarrhea for the past 3 days, after a week of constipation. He and his family recently returned from a summer spent in New Delhi, India visiting relatives. Physical examination reveals abdominal tenderness and a pink macular rash extending from his trunk to his upper arms. His vital signs are as follows: temperature is 99.7°F (37.6°C), blood pressure is 120/72 mmHg, pulse is 85/min, and respirations are 16/min. Which of the following drugs would be most effective in treating this patient’s condition?

A 59-year-old man comes to the physician because of a painful, burning red rash on his face and hands, which developed 30 minutes after going outside to do garden work. He wore a long-sleeved shirt and was exposed to direct sunlight for about 10 minutes. The patient is light-skinned and has a history of occasional sunburns when he does not apply sunscreen. The patient was diagnosed with small cell lung carcinoma 2 months ago and is currently undergoing chemotherapy. He is currently taking demeclocycline for malignancy-associated hyponatremia and amoxicillin for sinusitis. He has also had occasional back pain. He takes zolpidem and drinks 1–2 glasses of brandy before going to sleep every night. He has smoked a pack of cigarettes daily for 20 years. His pulse is 72/min and his blood pressure is 120/75 mm Hg. Physical examination shows prominent erythema on his forehead, cheeks, and neck. Erythema and papular eruptions are seen on the dorsum of both hands. Which of the following is the most likely cause of this patient's symptoms?

A 48-year-old woman with a history of osteoarthritis and hypertension presents to the office complaining of persistent abdominal pain for the last 2 months. She describes the pain as 'burning and achy' that is worse when she eats, which has lead to a weight loss of 4.5 kg (10.0 lb). The patient is currently taking lisinopril and atenolol for her blood pressure and ibuprofen as needed for her osteoarthritis. Her temperature is 37.1°C (98.7°F), heart rate is 75/min, and blood pressure is 120/80 mm Hg. An endoscopy is performed and a gastric ulcer is visualized and biopsied. The biopsy reveals H. pylori infection. Which of the following is the most likely predisposing factor to this patient’s diagnosis?

A 64-year-old woman presents to the emergency room with complaints of severe, whole-body itching. She states that she first noticed her symptoms while in the bathtub at home. She has never had symptoms like this before. However, over the previous several months she has had episodes of severe joint swelling and pain in her hands as well as redness, burning pain, and swelling of her hands and feet. Her past medical history is significant for type II diabetes mellitus, hypertension, and osteoporosis for which she takes metformin, enalapril, and alendronate, respectively. In addition, she was found to have a deep vein thrombosis of her left leg three months prior to presentation. The patient’s temperature is 98.6°F (37.0°C), pulse is 80/min, blood pressure is 135/85 mmHg, and respirations are 13/min. Physical exam is notable for a woman in discomfort with excoriations over the skin on her forearms. The patient’s laboratory tests are shown below. Serum: Na+: 135 mEq/L Cl-: 100 mEq/L K+: 5.0 mEq/L HCO3-: 22 mEq/L BUN: 19 mg/dL Glucose: 130 mg/dL Creatinine: 1.0 mg/dL Hematocrit: 64% Leukocyte count: 19,000 cells/mm^3 with normal differential Platelet count: 900,000/mm^3 What is the best next step in treatment of this patient's underlying condition?

A 32-year-old man presents with a 1-week history of progressive diplopia followed by numbness and tingling in his hands and feet, some weakness in his extremities, and occasional difficulty swallowing. He was recently diagnosed with Hodgkin's lymphoma and started on a chemotherapeutic regimen that included bleomycin, doxorubicin, cyclophosphamide, vincristine, and prednisone. He denies fever, recent viral illness, or vaccination. On neurological examination, he has bilateral ptosis. His bilateral pupils are 5 mm in diameter and poorly responsive to light and accommodation. He has a bilateral facial weakness and his gag reflex is reduced. Motor examination using the Medical Research Council scale reveals a muscle strength of 4/5 in the proximal muscles of upper extremities bilaterally and 2/5 in distal muscles. In his lower extremities, hip muscles are mildly weak bilaterally, and he has bilateral foot drop. Deep tendon reflexes are absent. Sensory examination reveals a stocking-pattern loss to all sensory modalities in the lower extremities up to the middle of his shins. A brain MRI is normal. Lumbar puncture is unremarkable. His condition can be explained by a common adverse effect of which of the following drugs?

A 26-year-old student arrives to student health for persistent diarrhea. She states that for the past 2 months she has had foul-smelling diarrhea and abdominal cramping. She also reports increased bloating, flatulence, and an unintentional 4 lb weight loss. Prior to 2 months ago, she had never felt these symptoms before. She denies other extra-gastrointestinal symptoms. The patient is an avid hiker and says her symptoms have caused her to miss recent camping trips. The patient has tried to add more fiber to her diet without relief. She feels her symptoms worsen with milk or cheese. Her medical history is insignificant and she takes no medications. She drinks whiskey socially, but denies smoking tobacco or using any illicit drugs. She is sexually active with her boyfriend of 2 years. She went to Mexico 6 months ago and her last multi-day backpacking trek was about 3 months ago in Vermont. Physical examination is unremarkable. A stool sample is negative for fecal occult blood. Which of the following is an associated adverse effect of the most likely treatment given to manage the patient’s symptoms?

A 29-year-old man presents to the primary care clinic in June for post-discharge follow-up. The patient was recently admitted to the hospital after a motor vehicle collision. At that time he arrived at the emergency department unconscious, hypotensive, and tachycardic. Abdominal CT revealed a hemoperitoneum due to a large splenic laceration; he was taken to the operating room for emergency splenectomy. Since that time he has recovered well without complications. Prior to the accident, he was up-to-date on all of his vaccinations. Which of the following vaccinations should be administered at this time?

A 55-year-old woman presents with diarrhea and a rash. She reports having some painful reddish nodules on her legs that she noticed a week ago. She also has been having loose stools associated with cramping lower abdominal pain for the past month. This is associated with an urgency to defecate, and defecation helps relieve the abdominal pain. The stool is occasionally blood-tinged and has some mucus. She feels fatigued but denies fever, weight loss, exposure to any sick people, or history of travel recently. No significant past medical history. Her family history is significant for osteoporosis in her mother, aunt, and older sister. On physical examination, the patient has generalized pallor. There are multiple erythematous tender nodules over the extensor surface of the legs bilaterally below the level of the knee. Abdominal examination reveals mild tenderness to palpation in the left lower quadrant. A DEXA scan is performed and reveals a T-score of -1.5 at the hips and spine. Laboratory findings are significant for microcytic anemia and an elevated ESR. A colonoscopy is performed and reveals patchy inflammation of the colon with rectal sparing. The lesions are present in patches with intermittent normal colonic mucosa. The patient is started on sulfasalazine and shows a good response. However, 6 months later, she returns with a recurrence of her symptoms. A repeat colonoscopy reveals more extensive involvement of the colon and the small bowel. A second drug is added to her treatment regimen. Which of the following is the most common adverse effect associated with the use of this second drug?

A laboratory physician investigates the chromosomes of a fetus with a suspected chromosomal anomaly. She processes a cell culture obtained by amniocentesis. Prior to staining and microscopic examination of the fetal chromosomes, a drug that blocks cell division is added to the cell culture. In order to arrest chromosomes in metaphase, the physician most likely added a drug that is also used for the treatment of which of the following conditions?

A 30-year-old man comes to the emergency department because of the sudden onset of back pain beginning 2 hours ago. Beginning yesterday, he noticed that his eyes started appearing yellowish and his urine was darker than normal. Two months ago, he returned from a trip to Greece, where he lived before immigrating to the US 10 years ago. Three days ago, he was diagnosed with latent tuberculosis and started on isoniazid. He has worked as a plumber the last 5 years. His temperature is 37.4°C (99.3°F), pulse is 80/min, and blood pressure is 110/70 mm Hg. Examination shows back tenderness and scleral icterus. Laboratory studies show: Hematocrit 29% Leukocyte count 8000/mm3 Platelet count 280,000/mm3 Serum Bilirubin Total 4 mg/dL Direct 0.7 mg/dL Haptoglobin 15 mg/dL (N=41–165 mg/dL) Lactate dehydrogenase 180 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 anemia?