Antimicrobials — MCQs

A 71-year-old man with colorectal cancer comes to the physician for follow-up examination after undergoing a sigmoid colectomy. The physician recommends adjuvant chemotherapy with an agent that results in single-stranded DNA breaks. This chemotherapeutic agent most likely has an effect on which of the following enzymes?

A 31-year-old woman presents to your office with one week of recurrent fevers. The highest temperature she recorded was 101°F (38.3°C). She recently returned from a trip to Nigeria to visit family and recalls a painful bite on her right forearm at that time. Her medical history is significant for two malarial infections as a child. She is not taking any medications. On physical examination, her temperature is 102.2°F (39°C), blood pressure is 122/80 mmHg, pulse is 80/min, respirations are 18/min, and pulse oximetry is 99% on room air. She has bilateral cervical lymphadenopathy and a visible, enlarged, mobile posterior cervical node. Cardiopulmonary and abdominal examinations are unremarkable. She has an erythematous induration on her right forearm. The most likely cause of this patient's symptoms can be treated with which of the following medications?

A drug that inhibits mRNA synthesis has the well-documented side effect of red-orange body fluids. For which of the following is this drug used as monotherapy?

A 52-year-old man presents to his physician with a chief concern of not feeling well. The patient states that since yesterday he has experienced nausea, vomiting, diarrhea, general muscle cramps, a runny nose, and aches and pains in his muscles and joints. The patient has a past medical history of obesity, chronic pulmonary disease, lower back pain, and fibromyalgia. His current medications include varenicline, oxycodone, and an albuterol inhaler. The patient is requesting antibiotics and a refill on his current medications at this visit. He works at a local public school and presented with a similar chief complaint a week ago, at which time he had his prescriptions refilled. You have also seen several of his coworkers this past week and sent them home with conservative measures. Which of the following is the best next step in management?

A 21-year-old girl with a history of bipolar disorder, now in a depressive episode, presents to the emergency in distress. She reports that she wanted to "end it all" and swallowed a full bottle of acetaminophen. However, regretting what it would do to her parents, and she decided that she wants to live. She appears in no acute distress and clearly states she swallowed the pills one hour ago. What is the most appropriate next step in management?

A 25-year-old woman with a psychiatric history of bipolar disorder is brought into the emergency department by emergency medical services. The patient is unconscious, but the mother states that she walked into the patient's room with the patient lying on the floor and an empty bottle of unknown pills next to her. The patient has previously tried to commit suicide 2 years ago. Upon presentation, the patient's vitals are HR 110, BP 105/60, T 99.5, RR 22. The patient soon has 5 episodes non-bilious non-bloody vomiting. Upon physical exam, she has pain in the right upper quadrant and her liver function tests are AST 1050 U/L, ALT 2050 U/L, ALP 55 U/L, Total Bilirubin 0.8 mg/dL, Direct Bilirubin 0.2 mg/dL. You are awaiting her toxicology screen. What is the most likely diagnosis?

A 38-year-old woman comes to the physician for a follow-up examination. Two years ago, she was diagnosed with multiple sclerosis. Three weeks ago, she was admitted and treated for right lower leg weakness with high-dose methylprednisone for 5 days. She has had 4 exacerbations over the past 6 months. Current medications include interferon beta and a multivitamin. Her temperature is 37°C (98.6°F), pulse is 90/min, and blood pressure is 116/74 mm Hg. Examination shows pallor of the right optic disk. Neurologic examination shows no focal findings. She is anxious about the number of exacerbations and repeated hospitalizations. She is counseled about the second-line treatment options available to her. She consents to treatment with natalizumab. However, she has read online about its adverse effects and is concerned. This patient is at increased risk for which of the following complications?

A 5-year-old boy is brought to the emergency room lapsing in and out of consciousness. The mother reports that 30 minutes ago, the young boy was found exiting the garage severely confused. A container of freshly spilled antifreeze was found on the garage floor. The next appropriate step would be to administer:

An experimental infusable drug, X729, is currently being studied to determine its pharmacokinetics. The drug was found to have a half life of 1.5 hours and is eliminated by first order kinetics. What is the minimum number of hours required to reach a steady state concentration of >90%?

A 2-year-old boy is brought to the physician for generalized fatigue and multiple episodes of abdominal pain and vomiting for the past week. His last bowel movement was 4 days ago. He has been having behavioral problems at home for the past few weeks as well. He can walk up stairs with support and build a tower of 3 blocks. He cannot use a fork. He does not follow simple instructions and speaks in single words. His family emigrated from Bangladesh 6 months ago. He is at the 40th percentile for height and weight. His temperature is 37°C (98.6°F), pulse is 115/min, and blood pressure is 84/45 mm Hg. Examination shows pale conjunctivae and gingival hyperpigmentation. His hemoglobin concentration is 10.1 g/dL, mean corpuscular volume is 68 μm3, and mean corpuscular hemoglobin is 24.5 pg/cell. The patient is most likely going to benefit from administration of which of the following?