Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Microbiology Part 1 > Lec21 Case Based Review of Antibiotics > Flashcards

Lec21 Case Based Review of Antibiotics Flashcards

1
Q

What is drug of choice for scarlet fever?

A

penicillin or amoxicillin [for strep A]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which of these is a common side effect of penicillin?

A. allergic rxn
B. bile sludging
C. ototoxicity
D. QTc prolongation
E. tendonitis
A

A. allergic rxn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which of these is a common side effect of ceftriaxone?

A. allergic rxn
B. bile sludging
C. ototoxicity
D. QTc prolongation
E. tendonitis
A

B. bile sludging

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which of these is a common side effect of aminoglycosides?

A. allergic rxn
B. bile sludging
C. ototoxicity
D. QTc prolongation
E. tendonitis
A

C. ototoxicity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which of these is a common side effect of azithromycin?

A. allergic rxn
B. bile sludging
C. ototoxicity
D. QTc prolongation
E. tendonitis
A

D. QTc prolongation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which of these are common side effects of fluoroquinolones?

A. allergic rxn
B. bile sludging
C. ototoxicity
D. QTc prolongation
E. tendonitis
A

QTc prolongation and tenodinits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How do you differentiate allergic rash vs rash not related to antibiotic?

A

allergic rash will have hives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the most important cause of septic arthritis?

A

staph aureus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is empiric treatment for septic arthritis of the following

A. ceftriaxone
B. cephalexin
C. Nafcillin
D. piperacillin-tazobactam
E. vancomycin
A

C. nafcillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is mech of MRSA being reisistant?

A

altered PBP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are 5 antibiotics most active against MRSA? 3 others that are pretty active?

A

most active

  • vancomycin = first line
  • daptomycin
  • linezolid
  • ceftaroline = only cephalosporin active against MRSA

pretty active

  • clindamycin
  • doxycycline
  • trimethoprim-sulfamethoxazole
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How is vancomycin administered? side effects? mech of action?

A

administered: IV

side effects: red man syndrome, nephrotoxicity

action: inhibits polymerization peptidoglycan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How is daptomycin administered? side effects? mech of action?

A

administered: IV

side effects: myositis, CPK elevation

action: disrupts bacterial membrane
notes: not active in lung because inactivated by surfactant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How is linezolid administered? side effects? mech of action?

A

administered: oral or IV [100% bioavaialbility]

side effects: bone marrow suppression, low platelets, serotonin syndrome

action: protein synthesis inhibitor
note: costly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How is clindamycin administered? mech of action?

A

administered: oral [good bioavailability]
action: protein synthesis inhibitor
note: excellent penetration to bone [good for osteomyelitis]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How is doxycycline administered? side effects? mech of action?

A

administered: oral, but absorption inhibited by Ca, Mg, dairy, antacids

side effects: photosensitivity, GI intolerance, staining of teeth in children

action: protein synthesis inhibitor [a tetracycline]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is mech of action of trimethoprim-sulfmethoxazole administered? side effects?

A

side effects: steven-johnson syndrome = rash and blisters all over body, bone marrow suppression, kern-icterus in infants

action: folate pathway inhibitor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which of the following is best definitive treatment for MSSA? Why?

A. amoxicillin
B. azythromycin
C. cefazolin
D. cefepime
E. penecillin
A

C. cefazolin

s. aureus usually produces penicillinase –> best to treat with penicillinase stable penicillin [nafcillin] or 1st gen cephalosporin [cefazolin, cephalexin]

other active but unnecessarily broad treatments:
4th gen cephalosporins: cefepime
5th gen: ceftaroline
beta lacam + betalactamase combo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the 3 beta lactam + betalactamase inhibitor combos?

A

Amoxicillin-clavulanic

Ampicillin-sulbactam

Piperacillin-tazobactam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is empiric antibiotic regimen for infant with meningitis?

A

vancomycin + ceftriazone

vanc = some strains of strep pneumo resistant to cetriaxone
ceft = strep pneumo, neisseria, h. influenzae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

who gets listeria?

A

less than 1 month
pregnant
immunocompromised

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are causes of bacterial meningitis for less than 1 month old? empiric treatment?

A

GBS, E Coli, Listeria

treat: ampicillin + cefotaxime

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are causes of bacterial meningitis for 1 month to adulthood? empiric treatment?

A

N. meningitidis, S. pneumoniae, H. influenza type B

treat: cetriaxone + vancomycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are causes of bacterial meningitis in immunocompromised and pregnant? empiric treatment?

A

N. meningitidis, S. pneimoniae, H. influenzae type B, Listeria

treat: ceftriaxone + vancomycin + ampicillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
If you have kid with s pneumoniae meningitis which of the following would you choose to treat it? A. ampicillin B. cefazolin C. cefuroxime D. clindamycin
A. ampicillin 1st and 2nd gen cephalosporins don't penetrate CNS [cefazlin, cefuroxime] clindamycin = bacteriostatic so not strong enough for meningitis [prefer bacteridicidal since so serious], also doesn't have great ability to penetrate CNS
26
What are the two first gen cephalosporins? how are they administered? what do they treat? Can they penetrate CNS?
cefazolin [IV], cephalexin [PO = oral] - gram pos but not MRSA or enterococcus - some gram neg [some E Coli, K pneumoniae] = best cephalosporins for MSSA Can't penentrate CNS
27
What are the 3 main second gen cephalosporins? how are they administered? what do they treat? Can they penetrate CNS?
Cefuroxime [IV or PO], Cefoxitin, Cefotetan treat: - 1st gen spectrum + broader gram negative - treat H. influenzae [sinusitis, otitis media] - cefoxitin and cefotetan = only 2nd gen cephs with anaerobic spectrum do not penetrate CNS
28
What are the main third gen cephalosporins? how are they administered? what do they treat? Can they penetrate CNS?
Ceftriazone [IV or IM], Cefotaxime [IV or IM] - activity against most community acquired, broader gram neg than 1st or 2nd gen - some s. pneumoniae are resistant - no MRSA, enterococcus, pseudomonas, anaerobes - penetrate all tissues including CNS - good empiric treat for meningitis, pneumonia, urinary infections
29
What is side effect of ceftriaxone? who should avoid?
- can get bile sludging because excreted in bile | - avoid in infants and people with liver disease
30
What kind of coverage does ceftazidime have?
- no gram positive coverage | - good for pseudomonas
31
Is half life longer for ceftriaxone or cefotaxime?
ceftriaxone = longer half life, 1-2 daily admin cefotaxime = shorter half life, 3x a day administration
32
What type of antibiotic used to empirically treat patient with leukemia, neutropenia? Hint: at high risk for bacterial sepsis including from pseudomonas?
- beta lactam with activity against gram +/gram-/pseudomonas - levofloxacin - add vancomycin to either if concerned for MRSA
33
What are betalactams with activity against psuedomonas?
penicillins: piperacillin +/- tazobactam, ticaracillin +/- clavulanic cephalosporins: ceftazidime [3rd gen], cefepime [4th gen] carbapenems: doripenem, imipenem-cilastatin, meropenem monobactams: aztreonam
34
What is aztreonam useful against?
- against pseudomonas - no gram + activity - good for pt with beta-lactam allergy
35
what is ceftazidime useful against?
- against pseudomonas | - no gram + activity
36
What is cefepime active against? how is it administered?
- IV administration treats: - same gram post coverage of 1st gen cephalosporins [no MRSA or enterococcus] - same gram neg coverage of 3rd gen cephalosporins - pseudomonas - other nosocomial gram neg
37
Why is shortcoming of piperacillin-tazobactam?
not good CNS penetration = don't use for meningitis
38
What is imipenem [and carbapenems] active against? how is it administered? side effect?
- IV administration treats: - gram pos [no MRSA] - gram neg [including borader nosocomial coverage than cefepime] - anaerobes side effect: associated with seizures
39
What are side effects of fluorquinolones? safe for kids? bioavailability? CNS penetration?
- side effect: tendonitis, QTc prolongation, CNS symptoms - not first line drug for kids --> concern about effect on bone growth - good bioavailability can give PO or IV - good CNS penetration
40
What is mech of resistance to fluoroquinolones?
resistance by mutation in topoisomerase or DNA gyrase
41
What can ciprofloxacin treat of the following? A. gram negative [including pseudomonas] B. gram pos [MRSA and enterococcus not consistently] C. anaerobes D. atypicals [mycoplasma, chlamydia, legionella]
Yes: A and D A. gram negative [including pseudomonas] D. atypicals [mycoplasma, chlamydia, legionella] Not: B. gram pos [MRSA and enterococcus not consistently] C. anaerobes
42
What can levofloxacin treat of the following? A. gram negative [including pseudomonas] B. gram pos [MRSA and enterococcus not consistently] C. anaerobes D. atypicals [mycoplasma, chlamydia, legionella]
Yes: A, B, and D A. gram negative [including pseudomonas] B. gram pos [MRSA and enterococcus not consistently] D. atypicals [mycoplasma, chlamydia, legionella] Not: C. anaerobes
43
What can moxifloxacin treat of the following A. gram negative [including pseudomonas] B. gram pos [MRSA and enterococcus not consistently] C. anaerobes D. atypicals [mycoplasma, chlamydia, legionella]
All!
44
What is mech of action of aminoglycosides? Activity? side effects? CNS penetration?
mech: protein synthesis inhibitors activity: - mostly gram negatives, usully not used as single agents - can be synergistic against some gram pos [with ampicillin against enterococcus] side effects: - ototoxic [auditory and vestibular] - nephrotoxic No CNS penetration!
45
What are the 3 aminoglycosides? what is broadest?
- Gentamicin - tobramycin - amikacin = broadest
46
What organism would you guess from: 24 yo male with AML, fever, neutropenia, on Cefepime. fever persisted and culture on day 6 grows gram + cocci in pairs and short chains
enterococci because gram + pairs and short chains that are common nosocomial pathogens and are not treatable by cephalosporins
47
What is the empiric treatment for serious enterococci infection? If resistant to this?
- vancomycin | - if resistant [VRE] use linezolid or daptomycin
48
What is the first line drug for susceptible enterococci strains?
ampicillin
49
What drugs cannot treat enterococci?
- cephalosporins have no activity - fluoroquinolones have poor activity - aminoglycosides have no activity on their own
50
What can ceftaroline treat?
- gram pos including MRSA - gram neg narrower than 4th gen - cannot treat pseudomonas or other resistant nosocomial negatives
51
``` Which of the following to treat pt with C difficile colitis? A. Ampicillin-sulbactam B. Piperacillin-tazobactam C. Imipenem D. Cefotetan E. Clindamycin F. Metronidazole ```
F. metronidazole
52
What can metronidazole treat? mech? type of administration? side effects?
treat: anaerobic bacteria, some parasites mech: causes DNA damage administration: IV or PO side effects: disulfiram effect [vomiting, ab pain, headache combined with alcohol], metallic taste, CNS side effects
53
What can oral vancomycin be used to treat?
- C difficile colitis | - second line drug because of concerns for selection of VRE and cost
54
Clinical: pt on day 7 of levofloxacin treatment of pneumonia presents with fever, ab main, foul-smelling bloody loose bowel movements What should you think?
C Diff colitis
55
What is cause of intra-abdominal abscess?
usually polymicrobial - anaerobes, enteric gram neg, enterococcus, anaerobic streptococci
56
What treatment for intra-abdominal abscess?
- cephalosporin [for gram -] + metronidazole [for anaerobes] - beta lactam/beta lactamase inhibitor - carbapenem also drain abscess
57
In order which is best for gram neg between: pip/tazo, imipenem, amp/sulbactam?
imipenem > pip/tazo > amp/sulbactam
58
Match the four main causes of pneumonia with the clinical situations? A. most common B. common after flu C. common in COPD D. common in alcoholic pt, older pts
``` A = s. pneumoniae B = s. aureus C = h. influenzae D = k. pneumoniae ```
59
What are causes of walking pneumonia?
- mycoplasma - chlamydia - legionella [sicker pts] - viruses
60
How do you treat walking pneumonia?
- azithromycin | - fluoroquinolones [levofloxacin]
61
Treatment for v. sick pneumonia pt [inpatient]?
- ceftrioxone [to cover typicals] and azithromycin [to cover atypicals] - levofloxacin - if S aureus suspected --> vancomycin
62
Treatment for outpatient pneumonia?
- levofloxacin [for lobar PNA and atypicals] | - amoxicillin +/- azithromycin [preferred for peds]
63
What are the 3 macrolides?
- azithromycin - clarithromycin - erythromycin
64
What is a side effect unique to clarithromycin and erythromycin?
CP450 inhibitors, can elevate levels of drugs metabolized through that pathway
65
What are side effects of the macrolides?
all: QTc prolongation erythromycin: GI discomfort clarithro + erythro: CP450 inhibitors --> elevate levels of drugs metabolized through that pathway

Microbiology Part 1 (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions