Step 1 Flash Cards > Antibacterials > Flashcards

Antibacterials Flashcards

(55 cards)

Study These Flashcards
1
Q

Penicillin mechanism

A

G - IV, V - oral

  • bind penicillin-binding proteins (transpeptidases)
  • block transpeptidase cross-linking of peptidoglycan
  • activate autolytic enzymes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

penicillin clinical use

A
  • usually used for gram +ves, bactericidal for gram positive cocci and rods, gram negative coci, and spirochetes
  • S. pneumo, S. pyogenes, Actinomyces, N. meningitidis, T. pallidum
  • “STAN’S” favorite drug is penicillin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

penicillin toxicity and resistance

A
  • tox: hypersensitivity reactions, hemolytic anemia

- resistance: penicillinase in bacteria cleaves B lactam ring

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

ampicillin, amoxicillin mechanism

A
  • same as penicillin, wider spectrum, also combined with clav to protect against b-lactamase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

amp/amox clinical use

A
  • extended spectrum penicillin - H flu, E coli, listeria, proteus, salmonella, shigella, enterococci
  • HELPSS kill enterococci
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

amp/amox tox and resistance

A
  • tox: hypersensitivity reactions, rash, pseudomembranous colitis
  • resistance: penicillinase in bacteria cleaves B lactam ring
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

oxacillin, nafcillin, dicloxacillin mechanism

A
  • same as penicillin, narrow spectrum because of bulky R group blocking access to B lactam ring
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

oxacillin, nafcillin, dicloxacillin clinical use and tox

A
  • s. aureus (not MRSA), skin/soft tissue infections

- tox: hypersensitivity reactions, interstitial nephritis

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

ticarcillin, piperacillin mechanism, clinical use and tox

A
  • same mechanism as penicillin, extended spectrum
  • used against psuedomonas and GNR, use with B lactamase inhibitors, susceptible to penicillinase
  • tox: HS reactions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

B lactamase inhibitors

A
  • CAST: clavulanic acid, sublactam, tazobactam

- added to penicillins to protect from destruction by B lactamase (penicillinase)

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

cephalosporin mechanism of action

A
  • B lactams that inhibit cell wall synthesis, but are less susceptible to penicillinases
  • bind to PBPs irreversibly, bactericidal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

1st gen cephalosporins clinical use

A
  • cephalexin, cefazolin

- PEcK - proteus, E coli, Klebsiella

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

2nd gen cephalosporin clinical use

A
  • cefoxitin, cefaclor, cefuroxime

- HEN PEcKs - H flu, Enterobacter, Neisseria, proteus, E coli, Klebs, Serratia

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

3rd gen cephalosporin clinical use

A
  • ceftriaxone, cefotaxime, ceftazidime
  • serious gram negative infections
  • ceftriaxone –> meningitis and gonorrhea
  • ceftazidime –> pseudomonas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

4th gen cephalosporin clinical use

A
  • cefepime

- increased activity against pseudomonas and gram positives

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

5th gen cephalosporin clinical use

A

-ceftaroline - broad GN and GP coverage, including MRSA but not psuedo

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

cephalosporin tox

A
  • HS reactions, Vit K deficiency, low cross-reactivity with penicillins, increased nephrotoxicity of aminoglycosides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

aztreonam mechanism and tox

A
  • a monobactam, resistant to B lactamases
  • prevents peptidoglycan cross-linking by binding to PBP3
  • synergistic with aminoglycosides
  • no cross-allergenicity with penicillins
  • usually non-tox, some GI upset
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

aztreonam clinical use

A

GNR only, no activity against gram + or anaerobes

- for pen allergic patients with renal insufficiency who cannot tolerate aminoglycosides

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

carbapenems mechanism

A
  • broad spectrum beta lactamase resistant
  • imipenem always given with cilastatin (inhibitor of renal dehydropeptidase I) to decrease inactivation of the drug in the renal tubules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

carbapenems clinical use and tox

A
  • gram + cocci, GNRs, and anaerobes
  • life-threatening infections
  • tox: GI distress, skin rash, seizures (dec risk with meropenem)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Vancomycin mechanism

A
  • inhibits cell wall peptidoglycan formation by binding D-ala D-ala portion of cell wall precursors
  • bactericidal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

vanc tox and mech of resistance

Study These Flashcards
A
  • NOT trouble free
  • nephrotoxic, ototoxic, thrombophlebitis
  • red man syndrome
  • bacteria change D-ala D-ala to D-ala D-lac to become resistant
24
Q

vanc clinical use

Study These Flashcards
A
  • gram positive only

- MRSA, enterococci and C. diff

25
protein synthesis inhibitors
buy AT 30, CCEL at 50 - 30s inhibitors: aminoglycosides (cidal), tetracyclines (static) - 50s inhibitors: chloramphenicol, clinda, erythromycin, linezolid (all static, linezolid is variable)
26
aminoglycosides (names)
gentamycin, neomycin, amikacin, tobramycin, streptomycin | - "Mean" (amino...) GNATS caNNOT kill anaerobes
27
aminoglycosides mechanism
bactericidal - inhibit formation of initiation complex and cause misreading of mRNA - also block translocation - require O2 for uptake, therefore ineffective against anaerobes
28
aminoglycosides clinical use
severe GNR infections - synergistic with beta lactams - neomycin for bowel surgery
29
aminoglycosides toxicity
caNNOT kill anaerobes | - nephrotoxic, neuromuscular blockade, ototoxic, teratogen
30
aminoglycosides mechanism of resistance
- bacterial transferase enzymes inactivate the drug by acetylation, phosphorylation, or adenylation
31
tetracyclines names and mechanism
- tetracycline, doxycycline, minocycline - bacteriostatic, bind to 30s and prevent attachment of aminoacyl-tRNA - limited CNS penetration - doxy is fecally eliminated and can be used in patients with renal failure - dont take with milk or antacids or iron because divalent cations prevent absorption
32
tetracyclines clinical use
- borrelia burgdorferi, M. pneumoniae - ability to accumulate intracellularly makes it good against rickettsia and chlamydia - also used to treat acne
33
tetracyclines tox and resistance
- tox: GI distress, discoloration of teeth and inhibition of bone growth in kids, photosensitivity - contraindicated in preggos - resistance: decreased uptake or increased efflux though plasmid-encoded transport pumps
34
macrolides mechanism and clinical use
- azithro, clarithro and erythromycin - inhibit protein synthesis by blocking translocation: bind to the 23S rRNA of the 50S - used in atypical pneumonia, STDs and g+ cocci
35
macrolides toxicity and resistance
- tox: MACRO -- GI Motility issues, Arrhythmia (prolonged QT), acute Cholestatic hepatitis, Rash, eOsinophilia - increases serum concentration of theophyllines, oral anticoagulants - resistance: methylation of 23S rRNA-binding site preventing binding of the drug
36
chloramphenicol mechanism and clinical use
- blocks peptidyltransferase at 50S ribosomal subunit, bacteriostatic - used in meningitis and RMSF
37
chloramphenicol tox and resistance
- tox: anemia, aplastic anemia, gray baby syndrome, | - resist: plasmid-encoded acetyltransferase inactivates the drug
38
clindamycin mechanism, clinical use and tox
blocks peptide transfer (translocation) at 50S - anaerobic infection in asp pneumo, lung anscesses and oral infections - also good for GAS - treats anaerobes above the diaphragm, metronidazole treats below the diaphragm - C diff, fever, diarrhea
39
sulfonamides mechanism and clinical use
- SMX, sulfisoxazole, sulfadiazine - inhibits folate synthesis, PABA antimetabolites inhibit dihydropteroate synthase, bacteriostatic - used for gram +, gram -ve, nocardia, chlamydia, UTI
40
sulfonamides tox and resistance
- HS reactions, hemolysis in G6PD, nephrotoxic, photosensitivity, kernicterus in infants, displace other drugs from albumin - resist: altered enzyme, decreased uptake or increased PABA synthesis
41
trimethoprim mechanism and tox
- inhibits bacterial dihydrofolate reductase | - tox: megaloblastic anemia, leukopenia, granulocytopenia (may alleviate with supplemental folic acid)
42
trimethoprim clinical use
- used in combo with SMX, causing sequential block of folate synthesis - UTI, shigella, salmonella, PCP and toxo prophylaxis
43
fluoroquinolones (-oxacins) mechanism and use
- inhibit DNA gyrase (topoisomerase II) and topo IV, bactericidal, must not be taken with antacids - used in GNR infections of GI and urinary tracts, neisseria, some g+
44
fluoroquinolone tox and resist
- tox: GI upset, superinfections, skin rashes, headache, dizziness - less commonly tendonitis, tendon rupture, leg cramps and myalgias - no preggos, nursing mothers and kids < 18 due to cartilage damage - may prolong QT - resist: chromosome-encoded mutation in DNA gyrase, plasmid-mediated resistance, efflux pumps
45
metronidazole mechanism and tox
- forms free radical toxic metabolites in the bacterial cell that damage DNA - bactericidal, antiprotozoal - tox: disulfram-like reaction (flushing, tachy, hypotension) with alcohol, headache, metalic taste
46
metronidazole clinical use
GET GAP on the metro | - giardia, entamoeba, trichomonas, gardnerella vaginalis, anaerobes, h Pylori
47
MAC treatment
- azithro or clarithro + ethambutol, can add rifabutin or cipro
48
leprae treatment
long term treatment with dapsone and rifampin for TB form | add clofazimine for lepromatous form
49
HIV prophylaxis
< 200 - TMP/SMX for PCP < 100 - TMP/SMX for PCP and toxo < 50 - azithro for MAC
50
MRSA treatment
vanco, dapto, linezolid, tigecycline, ceftaroline
51
VRE treatment
linezolid and streptogramins
52
INH mechanism, use and tox
- decreased sythesis of mycolic acids, catalase needed to convert INH to active metabolite - only solo prophylaxis for TB - tox: INH Injures Neurons and Hepatocytes - B6 can prevent neurotox
53
Rifamycins mech, use, tox
- inhibit DNA-dep RNA polymerase - used for TB, delays resistance to dapsone for leprosy - only indication for monotherapy is meningococcal prophylaxis - can also be used for HiB prophylaxis in contacts - tox: minor hepatotox and inc 450, orange body fluids (rifabutin> rifampin in HIV b/c less p450 stim)
54
pyrazinamide mech, use, tox
- uncertain mechanism, effective at acidic pH - used for TB - tox: hyperyuricemia, hepatotox
55
ethambutol mech, use, tox
- mech: decreased polymerization of mycobacterium cell wall by blocking arabinosyltransferase - used in TB - tox: optic neuropathy (R/G color blindness)
Step 1 Flash Cards
flashcards
Decks in class (36)
# Cards
Brainscape helps you reach your goals faster, through stronger study habits.
© 2026 Bold Learning Solutions. Terms and Conditions