Antibacterial Drugs Flashcards Preview

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Flashcards in Antibacterial Drugs Deck (60)
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1
Q

clostridium perfringens

A

metronidazole, chloramphenicol, penicillin G

2
Q

what kind of killers are beta lactams? what does this imply?

A

time-dependent; since they have short half-lives you need shorter dosing intervals

3
Q

penicillin G and V: spectrum

A
  • gram positive anaerobes (notably, C. perfringens)
  • gram positive (notably, 1st line for strep throat)
  • narrow gram negative: neisseria meningiditis
  • Syphilis
4
Q

what is oxacillin?

A

a beta lactam penicillin antibiotic used against beta-lactamase-positive staph

5
Q

amoxicillin: class, uses

A
  • beta lactam
  • otitis media in children caused by strep pneumoniae
  • alternate choice for Lyme disease
6
Q

2 important uses that ampicillin has that amoxicillin doesn’t

A

meningitis, GI infections

7
Q

otitis media by strep pneumoniae (2)

A

amoxicillin, TMP/SMX

8
Q

ticarcillin: class, uses

A
  • beta lactam

- broad gram negative spectrum (notably, Pseudomonas aeruginosa)

9
Q

piperacillin: class, uses

A
  • beta lactam

- broad gram negative spectrum like ticarcillin, but also more Pseudomonas and Klebsiella

10
Q

pseudomonas aeruginosa

A

CC TT PNG

ciprofloxacin, ceftazidime, ticarcillin, tobramycin, piperacillin, norfloxacin, gentamicin

11
Q

mechanism of clavulanic acid and tazobactam

A

beta-lactam “analogs” that bind irreversibly to beta-lactamase

12
Q

mechanism of beta-lactams

A

competitively and irreversibly inhibit PBPs which catalyze cell wall cross-links

13
Q

mechanism of cephalosporins

A

they are beta-lactams = competitively and irreversibly inhibit PBPs

14
Q

1st generation cephalosporins: uses, two drugs

A
  • gram positive
  • surgical prophylaxis for skin flora
  • drugs: cefazolin, cephalexin
15
Q

surgical prophylaxis for skin flora

A

cefazolin

16
Q

3rd generation cephalosporins: uses, two drugs

A
  • gram negative

- ceftriaxone, ceftazidime

17
Q

ceftriaxone: uses

A
  • common types of meningitis

- gonorrhea

18
Q

ceftazidime: use

A

Pseudomonas aeruginosa

19
Q

only beta-lactam with no cross-reaction with other beta-lactams

A

aztreonam

20
Q

imipenem: what it is, uses

A
  • broad spectrum beta lactam resistant to many beta-lactamases
  • mixed, ill-defined, resistant infections (notably, C. perfringens)
21
Q

aztreonam: what it is, use, unique aspect

A
  • beta lactam
  • gram negative aerobes
  • no allergic cross-reactions with beta lactams
22
Q
  • beta lactam
  • gram negative aerobes
  • no allergic cross-reactions with beta lactams
A

aztreonam

23
Q

vancomycin: what it is, -cidal or -static, mechanism, uses

A
  • glycopeptide antibiotic
  • bactericidal
  • binds to free end (D-Ala-D-Ala) of pentapeptide, which interferes with crosslinking and elongation of peptidoglycan chains
  • gram positives ONLY (notably, MRSA and C. difficile)
24
Q

fosfomycin: mechanism, uses

A
  • inhibits synthesis of peptidoglycan building blocks

- use: uncomplicated UTIs caused by E. coli, Enterococcus (2 F’s for 2 E’s)

25
Q

bacitracin: what it is, mechanism, use

A
  • polypeptide
  • interferes with lipid carrier that moves cell wall components through cell membrane
  • topical use only, gram positive spectrum
26
Q

polymyxin B: mechanism, uses

A
  • cationic detergent that binds LPS in the outer membrane of gram negatives
  • topical use only, gram negative spectrum
27
Q

daptomycin: mechanism, uses

A
  • binds to bacterial cytoplasmic membrane, causing rapid membrane depolarization
  • gram positive (notably, MRSA)
28
Q

cell membrane agents

A

polymyxin B and daptomycin

29
Q

quinolones: mechanism, -static or -cidal, killing type, drugs, side effects

A
  • inhibits DNA gyrase –> interferes with supercoiling
  • bactericidal; killing dependent on area under the curve
  • norfloxacin, ciprofloxacin, moxifloxacin
  • side effects: EKG irregularities, tendon rupture, seizures
30
Q

quinolones used for UTIs

A

norfloxacin, ciprofloxacin

31
Q

ciprofloxacin: what it is, uses

A
  • quinolone

- useful for infections at many sites: UTIs, chlamydia

32
Q

moxifloxacin: what it is, uses

A
  • quinolone
  • best gram positive activity out of quinolones
  • respiratory infections: community-acquired pneumonia and bacterial bronchitis
33
Q

community-acquired pneumonia (2)

A

moxifloxacin, tigecycline

34
Q

nitrofurantoin: mechanism, uses, side effects

A
  • converted to reactive compounds which can damage DNA
  • UTIs
  • side effects: acute and chronic liver damage, leukopenia, acute hemolytic anemia
35
Q

rifampin: mechanism, -static or -cidal, uses, side effects

A
  • inhibits bacterial RNA synthesis by binding RNA polymerase
  • bactericidal
  • uses: tuberculosis, meningitis prophylaxis (neisseria meningitidis, haemophilus influenza type b)
  • side effects: serious hepatotoxicity, strongly induces hepatic CYPs, orange colors to bodily fluids
36
Q

fidaxomicin: use

A

C. difficile

37
Q

metronidazole: mechanism, -static or -cidal, uses

A
  • anaerobes reduce the nitro group of metronidazole –> resulting product damages DNA
  • bactericidal
  • uses: anaerobes (C. difficile, C. perfringens), H. pylori, gardnerella vaginalis, giardia
38
Q

C. difficile enterocolitis: causes, treatment

A
  • can be caused by all antibacterials, consider in all patients with antibacterial drugs in last 2 months
  • metronidazole (first choice), vancomycin, fidaxomicin
39
Q

aminoglycosides: mechanism, -static or -cidal, uses, drugs, what kind of killing

A
  • bind to 30S/50S interface; inhibits protein synthesis
  • bactericidal
  • gram negative aerobes
  • tobramycin, amikacin, gentamicin
  • concentration-dependent killers
40
Q

why are aminoglycosides bad at killing anaerobic microbes?

A

they need to be transported into bacteria by an energy-requiring aerobic process

41
Q

what is a drug you could give to someone with strep throat who has a penicillin allergy?

A

clarithromycin

42
Q

tetracyclines: mechanism, -static or -cidal, uses, drugs, side effects

A
  • bind to 30S ribosomal subunit
  • bacteriostatic
  • preferred agents for “unusual bugs”=rickettsia, lyme disease, chlamydia; also syphilis and gonorrheae
  • doxycycline, minocycline
  • side effects: teeth discoloration (contraindicated in children and pregnancy)
43
Q

what class of drugs show post-antibiotic effect? name the drugs.

A

aminoglycosides: tobramycin, gentamicin, amikacin

44
Q

what drug class are doxycycline and minocycline in?

A

tetracyclines

45
Q

what drug class are tobramycin, gentamicin, amikacin in?

A

aminoglycosides

46
Q

tigecycline: mechanism, -static or -cidal, use

A
  • mechanism like tetracyclines (binds to 30S subunit) but also binds to other sites
  • bacteriostatic
  • broad spectrum (notably, MRSA, C. perfringens), but last line due to risk of death
47
Q

chloramphenicol: mechanism, -static or -cidal, use, side effects

A
  • binds 50S subunit
  • bacteriostatic
  • broad spectrum (notably, C. perfringens) but last line due to serious side effects
  • side effects: bone marrow depression, blindness
48
Q

macrolides: mechanism, -static or -cidal, drugs

A
  • binds 50S subunit, blocks translocation along ribosomes
  • bacteriostatic
  • erythromycin, clarithromycin, azithromycin
49
Q

erythromycin: what it is, -static or -cidal, mechanism, uses, side effects

A
  • macrolide
  • bacteriostatic
  • binds 50S subunit and blocks translocation along ribosomes
  • gram positive (notably, Strep. A pharyngitis)
  • side effects: enhanced GI motility, inhibits CYP3A metabolism, CV effects
50
Q

clarithromycin: what it is, -static or -cidal, mechanism, why it’s better than erythromycin, uses

A
  • macrolide
  • bacteriostatic
  • binds 50S subunit and blocks translocation along ribosomes
  • better kinetics/less frequent dosing than erythromycin, less GI motility effects, wider spectrum
  • spectrum similar to erythromycin + others (notably, used with amoxicillin plus an acid blocker to treat H. pylori)
51
Q

azithromycin: what it is, -static or -cidal, mechanism, uses

A
  • macrolide
  • bacteriostatic
  • binds 50S subunit and blocks translocation along ribosomes
  • outpatient respiratory tract infections (notably, Strep. pneumoniae)
  • genital infections: chlamydia, gonorrheae
52
Q

clindamycin: what it is, -static or -cidal, mechanism, uses

A
  • NOT a macrolide but same mechanism
  • bacteriostatic
  • binds 50S subunit and blocks translocation along ribosomes
  • gram positive, anaerobes (notably, C. perfringens)
53
Q

linezolid: mechanism, -static or -cidal, uses, side effects

A
  • binds to 50S subunit, preventing formation of 70S complex
  • gram positive (notably, MRSA)
  • VRE
  • side effects: non-selective inhbitor of MAO, bone marrow suppression
54
Q

first choice therapy for uncomplicated UTIs

A

TMP/SMX

55
Q

1st line for strep throat

A

penicillin V

56
Q

syphilis

A

penicillin G&V, tetracyclines (doxy- and mino-cycline)

57
Q

best treatment for bacterial meningitis

A

ceftriaxone+vancomycin

58
Q

quinolone for respiratory infections: community-acquired pneumonia and bacterial bronchitis

A

moxifloxacin

59
Q

quinolone with best gram positive activity

A

moxifloxacin

60
Q

meningitis prophylaxis (neisseria meningitidis, haemophilus influenza type b)

A

rifampin