Antibiotics Problem Solving Flashcards
Case 1
: A 20 year old male with a history of IV drug abuse presents to the ED with a left forearm abscess. He complains of fever and chills for the past 24 hours.
Vitals: BP 118/68, HR 98, T38.4°C
Labs: WBC 14.6, Scr 1.0
Question 1: Which of the following is the most appropriate medical management for this
patient?
A. IV meropenem and IV vancomycin
B. IV clindamycin
C. IV levofloxacin
D. IV piperacillin/tazobactam and IV vancomyci
Answer:
D. IV piperacillin/tazobactam and IV vancomycin
Discussion:
The patient meets the definition for sepsis in that he has a temperature > 38.3° C, tachycardia (> 90 bpm), leukocytosis (>12,000 WBC), and source of infection (forearm abscess)
The differential for potential pathogens in this case is
broader than in other skin abscesses .Infecting microorganisms include skin flora, contaminated drugs, and even oral flora. It is not uncommon for IV drug users to “clean” the needle or skin with saliva prior to injecting
The most common pathogens are: S. aureus or streptococci followed by anaerobic cocci and aerobic Gram -negative rod
Case 1: A 20 year-old male with a history of IV drug abuse presents to the ED with a leftforearm abscess. He complains of fever and chills for the past 24 hours.
Vitals: BP 118/68, HR 98, T 38.4°C
Labs: WBC 14.6, Scr 1.0
Question 2:On day 3 of therapy, the patient develops a maculopapular rash, fever and his Scr has increased to 1.5. Nephrology consultation was sought. Urinalysis revealed a cloudy specimen with specific gravity 1.017, 9 WBC with 1% eosinophils.
Which of the following is the most likely cause of his AKI? A. ATN from vancomycin B. AIN from vancomycin C. AIN from piperacillin-tazobactam D. ATN from piperacillin-tazobactam
C. AIN from piperacillin-tazobactam
Discussion: Antibiotics are responsible for 30-49% of drug-induced AIN. Of the antibiotics that cause
AIN, rifampin, sulfonamide and β-lactams are
the most common. Patients with drug-induced AIN
may also have an allergic response, although not
always. One or more signs of allergy are present in roughly one quarter of patients. Urine eosinophils may be present in AIN, but their absence does not exclude AIN.
The constellation of fever, rash and elevation in Scr point toward AIN, and piperacillin-tazobactam is a more likely culprit, although AIN has been reported with vancomycin.
Case 1: A 20 year-old male with a history of IV drug abuse presents to the ED with a left forearm abscess. He complains of fever and chills for the past 24 hours.
Vitals: BP 118/68, HR 98, T 38.4°C
Labs: WBC 14.6, Scr 1.0
Question 3: Blood cultures grow MRSA. The patient continues vancomycin and remains clinically stable, but repeat blood cultures continue to grow MRSA.
Which of the following is the best next step?
A. Add gentamicin 1 mg/kg q8h for synergy with vancomycin
B. Add rifampin 300 mg IV q12h for synergy with vancomycin
C. Change therapy to daptomycin 8 mg/kg daily
D. Perform a TEE to evaluate the cause of persistent bacteremia
D. Perform a TEE to evaluate the cause of persistent bacteremia
A 20 year-old male with a history of IV drug abuse presents to the ED with a left forearm abscess. He complains of fever and chills for the past 24 hours.
Vitals: BP 118/68, HR 98, T 38.4°C
Labs: WBC 14.6, Scr 1.0
Question 4: The patient is irate that he has to stay in the hospital for 6 weeks, and is demanding to go home.
Which of the following is the best oral option to send him home with? A. Linezolid 600 mg PO bid B. Bactrim DS PO bid C. Clindamycin 300 mg PO tid D. Doxycycline 100 mg PO bid E. None of the above
Answer: E. None of the above
TB is a 24 year-old male with cerebral palsy
and paraplegia who presents with a stage IV sacral decubitus ulcer. He was recently treated with piperacillin
-tazobactam and vancomycin for 6 weeks for the same ulcer which started to form granulation tissue, but
worsened after the antibiotics were discontinued.
Vitals: Temp 37.6, RR 18, Pulse 78
Labs: WBC 8.9, Scr 0.4
Question 1:
Which of the following antimicrobial regimens are appropriate to start right away?
A. Fluconazole + meropenem
B. Linezolid + piperacillin-tazobactam
C. Meropenem + vancomycin
D. Ampicillin-sulbactam + vancomycin
E. None of the above: wait for cultures to be obtained fir
E. None of the above: wait for cultures to be obtained first
TB is a 24 year-old male with cerebral palsy and paraplegia who presents with a stage IV sacral decubitus ulcer. He was recently treated with piperacillin
-tazobactam and vancomycin for 6 weeks for the same ulcer which started to form granulation tissue, but
worsened after the antibiotics were discontinued.
Weight 87 kg, Height 177.8 cm
Vitals: Temp 37.6, RR 18, Pulse 78
Labs: WBC 8.9, Scr 0.4
Question 2: The patient is started on meropenem and vancomycin awaiting culture results. The cultures are finalized with the following results: Pseudomonas aeruginosa Ceftazidime R MIC ≥8 CiprofloxacinR > 1 Gentamicin S MIC≤4 Meropenem R MIC≥4 Piperacillin-tazobactam R MIC≥32 Tobramycin S MIC≤1
Which of the following antibiotic regimens do you choose? A.Gentamicin 180 mg IV q8h B. Gentamicin 560 mg IV q24h C. Tobramycin 180 mg IVq8h D. Tobramycin 560 mg IV q24
Answer: D. Tobramycin 560 mg IV q24h
TB is a 24 year-old male with cerebral palsy and paraplegia who presents with a stage IV sacral decubitus ulcer. He was recently treated with piperacillin
- tazobactam and vancomycin for 6 weeks for the same ulcer which started to form granulation tissue, but
worsened after the antibiotics were discontinued.
Weight 87 kg, Height 177.8 cm
Vitals: Temp 37.8, RR 18, Pulse65
Labs: WBC 6.8, Scr 0.8
Question 3
The patient has been doing well on tobramycin 180 mg IV q8h for the past two weeks, but you’ve noticed that his urine output has declined. His Scr remains normal at 0.8. Which of the following is the most appropriate course of action?
A. Continue with the current dose of tobramycin
B. Recheck a peak tobramycin concentration
C. Obtain a tobramycin trough concentration
D. Switch to gentamicin
Answer:C.Obtain a tobramycin trough concentration
Case 3: AC is a 46 year-old female with a h/o renal stones who presents with L. flank pain, fever and nausea
to you, her primary care physician. Her last UTI was over a year ago, and she has not had any antibiotics in the last 3 months.
Question 1:
Which of the following is the best empiric choice?
A. Ampicillin
B. Ciprofloxacin
C. Amoxicillin/clavulanate (Augmentin)
D. Sulfamethoxazole/trimethoprim (Bactrim
Answer: C. Amoxicillin/clavulanate (Augmentin)
AC is a 46 year-old female with a h/o renal stones who presents with L. flank pain, fever and nausea to you, her primary care physician. Her last UTI was over a year ago, and she has not had any antibiotics in the last 3 months.
Question 2: You astutely pull out your community antibiogram before prescribing an antibiotic.
Based on the following, which is the most appropriate empiric choice?
E. coli(% susceptible)
Ampicillin 60%
Ciprofloxacin 81%
Amoxicillin/clavulate 88%
Bactrim 83%
A. Ampicillin
B. Ciprofloxacin
C. Amoxicillin/clavulanate (Augmentin)
D. Sulfamethoxazole/trimethoprim (Bactrim)
Answer: C. Amoxicillin/clavulanate (Augmentin)
You take over the care for a 38 year-old patient with HIV who has been out of the country for a decade. He has been on monotherapy with an NRTI during that time.
His most recent set of lab values note a CD4 count of 43.
Question 1: When asked, the patient states that he has not seen a physician for the last decade, and was getting his drugs from a friend who works for an international aid group; he took his medications religiously.
What is your next step?
A. Switch the patient to a different NRTI
B. Switch the patient to a protease inhibitor
C.Start the patient on a four drug cocktail
D.Start the patient on a three drug cocktail
E. Recommend end-of-life care
Answer: D.Start the patient on a three drug cocktail
You take over the care for a 38 year-old patient with HIV who has been out of the country for a decade.
He has been on monotherapy with an NRTI during that time. His most recent set of lab values note a CD4 count of 43.
Question 2: What medications must the patient take in addition to his HAART therapy to prevent opportunistic infections?
A.TMP-SMX alone B. Azithromycin alone C. Isoniazid alone D. TMP-SMX and azithromycin E. TMP-SMX and isoniazi
Answer: D. TMP-SMX and azithromycin
You take over the care for a 38 year-old patient with HIV who has been out of the country for a decade.
He has been on monotherapy with an NRTI during that time. His most recent set of lab values note a CD4 count of 43.
Question 3:
A few weeks into his treatment, the patient presents
complaints of consistent nausea and laboratory testing reveals worsening anemia. What should you do?
A.Start patient on a three drug combination regimen which does not include zidovudine
B.Start patient on a three drug combination regimen which includes a lower dose of zidovudine
C. Switch the patient from zidovudine monotherapy to tenofovir monotherapy
D. Switch the patient from zidovudine monotherapy to monotherapy with a protease inhibitor
E. Discontinue all antiretroviral therapy. This patient does not qualify for therapy.
Answer: A. Start patient on a three drug combination regimen which does not include zidovudine
You take over the care for a 38 year-old patient with HIV who has been out of the country for a decade.
He has been on monotherapy with an NRTI during that time. His most recent set of lab values note a CD4 count of 43.
Question 4: While vaccinating the patient against pneumococcus, you accidentally stick yourself with the needle after already injecting the patient. What is the correct sequence for treatment?
A.HIV test in one month, with treatment following positive viral load
B. Immediate prophylaxis with a three drug
regimen for four weeks, immediate HIV test, and follow up HIV test in one month
C. Immediate prophylaxis with a three drug cocktail for four weeks and follow up HIV test in one month
D.Immediate prophylaxis with a protease inhibitor for one week and follow up HIV test in one month
E. Immediate prophylaxis with a protease inhibitor for four weeks and follow up HIV test in one month
Answer: B. Immediate prophylaxis with a three drug
regimen for four weeks, immediate
HIV test, and follow up HIV test in one month
