Mechanisms
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100
This class of antibiotics is famous for being time-dependent and bactericidal.
What is beta-lactams?
100
The most common mechanism of resistance against beta-lactam antibiotics.
What is beta-lactamases?
100
I am a once daily alternative to linezolid that maintains activity against some linezolid-resistant staphylococcus and enterococcus (with cfr gene mediated resistance).
What is tedizolid?
100
Four components of pharmacokinetics.
What is absorption, distribution, metabolism, and elimination? (What the body does to the drug)
100
Bacteremia with this organism should prompt work-up for colon cancer.
What is Streptococcus bovis?
200
Mechanism of action of aminoglycosides.
What is irreversibly bind to 30S ribosomal subunit to cause misreading? Aminoglycosides are bactericidal, concentration depedent, and have a good post antibiotic effect.
200
Enterococci express low affinity PBPs (5 in faecium and 4 in faecalis) which are not targets for this class of antibiotics, rendering them intrinsically resistant.
What are cephalosporins? (exception: ceftaroline and ceftobiprole which have limited activity)
200
In 2016, this drug FDA approved for treatment of skin and soft tissue infections was granted approval for a single dose regimen administered over 30 minutes which helped it compete with The Medicine Company's single dose product (in the same class) administered over 3 hours.
What is dalbavancin?
200
Pharmacodynamic target for optimal activity of vancomycin against Staphylcococcus aureus.
What is AUC:MIC of 400? (Will also accept target trough of 15-20 mcg/ml for deep-seeded infections). Moise-Broder et al. examined the relationship between the vancomycin AUC/MIC and the outcomes of 108 patients with methicillin-resistant S. aureus pneumonia. An AUC/MIC value of 400 was associated with a successful outcome, whereas an AUC/MIC value of <400 was associated with a lower eradication rate and a highermortality rate (P<.005)
200
I'm a last resort for Pseudomonas, Acinetobacter, and some Enterobacteriaecae, but I don't have any activity against gram positives, Burkholderia, Proteus, Providencia, or Serratia.
What is colistin?
300
The mechanism of action of daptomycin.
Insertion of the lipophilic daptomycin tail into the bacterial cell membrane causes rapid membrane depolarization and a potassium ion efflux. This is followed by arrest of DNA, RNA and protein synthesis resulting in bacterial cell death.
300
The reason mecA gene conferred alternation of PBP2a does not decrease activity of ceftaroline against MRSA.
What is ceftaroline binds to PBP2b?
300
Both antibiotics approved in 2014 and 2015 for treatment of complicated intra-abdominal infections lack activity against these important pathogens often present in intra-abdominal infections.
What is anaerobes? (B. fragilis)
300
Pharmacodynamic target for aminoglycosides.
What is Cmax:MIC of at least 10?
300
I am the drug of choice for Stenotrophomonas maltophilia.
What is trimethoprim/sulfamethoxazole?
400
Because of its dual mechanism of action, this semisynthetic lipoglycopeptide antibiotic has maintained 100% activity when tested against VISA.
What is telavancin? (inhibits bacterial cell wall synthesis by interfering with peptidoglycan cross-linking, and also depolarizes bacterial membranes to disrupt barrier function).
400
The four major mechanisms of resistance against antibiotics.
What is target site alteration, enzyme-destruction, efflux pumps, and penetration of cell membranes (porin site alteration)?
400
This beta-lactamase inhibitor is unique in that it is recycled after deacylation (not hydrolyzed), restoring it to full activity.
What is avibactam?
400
Name two commonly used antimicrobials that should be dosed based on adjusted body weight in obesity.
What is acyclovir, aminoglycosides, or daptomycin?
400
The regimen for PCN-suscpetible Enterococcal endocarditis in patient with renal dysfunction or high-level resistance to aminoglycosides.
What is Ampicillin 2 g IV q 4 h (renally adjusted) plus ceftriaxone 2 g IV q 12 h for 6 weeks?
500
Name three classes of antibiotics at are "DNA disruptors" (ie work against DNA synthesis).
What is antifoltates (TMP/SMX), fluoroquinolones, and nitroimidazoles (metronidazole)? TMP/SMX- interfere with folic acid production at 2 steps which interferes with purine & DNA metabolism FQ- topoisomerase II and I Metronidazole- cytotoxic metabolite damages DNA
500
Based on the susceptibility profile below, what is the most likely mechanism of resistance? Blood culture: K. pneumoniae Amikacin <= 2 S Ampicillin >32 R Aztreonam > 16 R Cefazolin > 64 R Cefoxitin <= 4 S Ceftazidime > 16 R Ceftazidime/avibactam <=8/4 S Piperacillin/tazobactam 32 I Meropenem <=1 S
What is ESBL-producing K. pneumoniae?
500
This new antibiotic, FDA approved for skin and soft tissue infections, causes false aPTT elevations. Therefore, heparin administration is contraindicated within 120 hours of it's administration.
What is oritavancin? Oritavancin binds to the phospholipid reagents in commonly used coagulation tests and artificially prolongs the aPTT and increases the INR. This interference with determination of the aPTT may persist for 120 hours. Interference with determination INR may persist for up to 24 hours.
500
When treating an infection, it's always important to consider drug penetration to the site of action. Which antifungal agent would be inappropriate for treatment of a CNS or ocular infection?
What is micafungin? (echinocandins)
500
Treatment for Babesia microti.
What is is atovaquone 750 mg BID plus azithromycin 500-1000 mg once, then 250 mg daily for 7-10 days? Will also accept clindamycin 600 mg TID plus quinine 650 mg (salt) TID X 7-10 days for severe disease.
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