Carbapenems and monobactams — MCQs

You are seeing a patient in clinic who recently started treatment for active tuberculosis. The patient is currently being treated with rifampin, isoniazid, pyrazinamide, and ethambutol. The patient is not used to taking medicines and is very concerned about side effects. Specifically regarding the carbohydrate polymerization inhibiting medication, which of the following is a known side effect?

A 58-year-old man comes to the physician because of severe muscle aches and fatigue for 3 days. Last week he was diagnosed with atypical pneumonia and treated with clarithromycin. He has hyperlipidemia for which he takes lovastatin. Physical examination shows generalized tenderness of the proximal muscles in the upper and lower extremities. Serum studies show an elevated creatine kinase concentration. This patient's current symptoms are most likely caused by inhibition of which of the following hepatic enzymes?

A 7-year-old boy comes to the physician because of a generalized rash for 3 days. Over the past 5 days, he has also had a high fever and a sore throat. His 16-year-old sister was treated for infectious mononucleosis 2 weeks ago. He returned from a summer camp a week ago. His immunizations are up-to-date. Three years ago, he required intubation after an allergic reaction to dicloxacillin. The patient appears ill. His temperature is 38.2°C (100.8°F). Examination shows circumferential oral pallor. Cervical lymphadenopathy is present. There is tonsillar erythema and exudate. A confluent, blanching, punctate erythematous rash with a rough texture is spread over his trunk and extremities. His hemoglobin concentration is 13.3 g/dL, leukocyte count is 12,000/mm3, and erythrocyte sedimentation rate is 43 mm/h. Which of the following is the most appropriate next step in management?

An 18-year old college freshman presents to his university clinic because he has not been feeling well for the past two weeks. He has had a persistent headache, occasional cough, and chills without rigors. The patient’s vital signs are normal and physical exam is unremarkable. His radiograph shows patchy interstitial lung infiltrates and he is diagnosed with atypical pneumonia. The patient is prescribed azithromycin and takes his medication as instructed. Despite adherence to his drug regimen, he returns to the clinic one week later because his symptoms have not improved. The organism responsible for this infection is likely resistant to azithromycin through which mechanism?

A 31-year-old female with a bacterial infection is prescribed a drug that binds the dipeptide D-Ala-D-Ala. Which of the following drugs was this patient prescribed?

You are a resident in the surgical ICU. One of the patients you are covering is a 35-year-old pregnant G1P0 in her first trimester admitted for complicated appendicitis and awaiting appendectomy. Your attending surgeon would like you to start the patient on moxifloxacin IV preoperatively. You remember from your obstetrics clerkship, however, that moxifloxacin is Pregnancy Category C, and animal studies have shown that immature animals exposed to fluoroquinolones like moxifloxacin may experience cartilage damage. You know that there are potentially safer antibiotics, such as piperacillin/tazobactam, which is in Pregnancy Category B. What should you do?

You are treating a neonate with meningitis using ampicillin and a second antibiotic, X, that is known to cause ototoxicity. What is the mechanism of antibiotic X?

A 44-year-old woman presents to her primary care physician for worsening dysuria, hematuria, and lower abdominal pain. Her symptoms began approximately 2 days ago and have progressively worsened. She denies headache, nausea, vomiting, or diarrhea. She endorses feeling "feverish" and notes to having foul smelling urine. She has a past medical history of Romano-Ward syndrome and is not on any treatment. She experiences profuse diarrhea and nausea when taking carbapenems and develops a severe rash with cephalosporins. Her temperature is 100.4°F (38C), blood pressure is 138/93 mmHg, pulse is 100/min, and respirations are 18/min. On physical exam, the patient appears uncomfortable and there is tenderness to palpation around the bilateral flanks and costovertebral angle. A urinalysis and urine culture is obtained and appropriate antibiotics are administered. On her next clinical visit urine studies and a basic metabolic panel is obtained, which is shown below: Serum: Na+: 140 mEq/L Cl-: 101 mEq/L K+: 4.2 mEq/L HCO3-: 22 mEq/L BUN: 20 mg/dL Glucose: 94 mg/dL Creatinine: 2.4 mg/dL Urinalysis Color: Yellow Appearance: Clear Blood: Negative pH: 7 (Normal 5-8) Protein: Negative Nitrite: Negative Leukocyte esterase: Negative Cast: Epithelial casts FeNa: 3% Urine culture Preliminary report: 10,000 CFU/mL E. coli Which of the following antibiotics was most likely given to this patient?

A 56-year-old man presents with breathlessness and altered mental status. The patient’s daughter says that he has been having high fever and cough for the last 3 days. Past medical history is significant for a recent hospitalization 5 days ago, following a successful coronary artery bypass grafting (CABG). In the post-operative period, he was in an intensive care unit (ICU) for 6 days, including 12 hours on mechanical ventilation. Current medications are aspirin and rosuvastatin. The patient’s daughter mentions that he has had anaphylactic reactions to penicillin in the past. His temperature is 39.4°C (103°F), pulse rate is 110/min, blood pressure is 104/78 mm Hg, and respiratory rate is 30/min. On physical examination, the patient is confused and disoriented and shows signs of respiratory distress and cyanosis. On chest auscultation, there is crepitus in the right lung. The patient is immediately started on oxygen therapy, intravenous fluids, and supportive care. After the collection of appropriate samples for bacteriological culture, treatment with empirical intravenous antibiotics are started. After 24 hours of treatment, the microbiology results indicate Pseudomonas aeruginosa infection. Antibiotic therapy is changed to a combination of aztreonam and tobramycin. Which of the following best describes the rationale for choosing this antibiotic combination?

A 70-year-old man presents to his primary care physician for a general checkup. He states that he has been doing well and taking his medications as prescribed. He recently started a new diet and supplement to improve his health and has started exercising. The patient has a past medical history of diabetes, a myocardial infarction, and hypertension. He denies any shortness of breath at rest or with exertion. An ECG is performed and is within normal limits. Laboratory values are ordered as seen below. Serum: Na+: 139 mEq/L Cl-: 100 mEq/L K+: 6.7 mEq/L HCO3-: 25 mEq/L Glucose: 133 mg/dL Ca2+: 10.2 mg/dL Which of the following is the most likely cause of this patient's presentation?