antibiotics Flashcards
1
Q
Which drugs block cell wall synthesis by inhibition of peptidoglycan cross-linking
A
Penicillin, methicillin, ampicillin, piperacillin, cephalosporins, aztreonam, imipenem
2
Q
which drugs block peptidoglycan synthesis
A
Bacitracin, vancomycin
3
Q
which drugs block nucleotide synthesis by inhibiting folic acid synthesis (involved in methylation)
A
Sulfonamides, Trimethoprim
4
Q
which drugs block DNA topoisomerase
A
Fluoroquinolones
5
Q
which drugs block mRNA synthesis
A
Rifampin
6
Q
which drug damages DNA
A
Metronidazole
7
Q
Which drugs block protein synthesis at 50S ribosomal subunit
A
Chloramphenicol, macrolides, clindamycin, streptogramins (quinupristin, dalfopristin), linezolid
8
Q
Which drugs block protein synthesis at 30S ribosomal subunit
A
Aminoglycosides, Tetracyclines
9
Q
Name types of penicillins
A
Penicillin G (IV and IM & Penicillin V (oral)
10
Q
Mechanism of penicillin
A
- binds penicillin-binding protein (pbp; transpeptidases– block transpeptidases cross-linking of peptidoglycan– active autolytic enzymes
11
Q
Clinical use of penicillin
A
- mostly for gram(+) organisms (S. pneumo, S. pyogenes, Actinomyces)– N. meningitidis, T.pallidum, Syphilis
12
Q
What are penicillins bactericidal for
A
- gram (+) cocci- gram (+) rods- gram (-) cocci- spirochetes
13
Q
Penicillin toxicity
A
NAME?
14
Q
Penicillin resistance caused by
A
beta lactamases cleave beta lactam ring
15
Q
Name the narrow spectrum penicillins
A
Oxacillin, nafcillin, dicloxacillin
16
Q
Mechanism of narrow spectrum penicillins
A
oxacillin, nafcillin, dicloxacillin- same as penicillin (binds PBP, block transpeptidases cross-linking peptidoglycans)
17
Q
Narrow spectrum penicillins – characteristics
A
oxacillin, nafcillin, dicloxacillin- penicillinase resistant because bulky R group which blocks access of beta lactamase to beta lactam ring
18
Q
clinical use of Narrow spectrum penicillins
A
oxacillin, nafcillin, dicloxacillin- S. aureus (except MRSA)
19
Q
Why is MRSA resistant to narrow specrum penicillins?
A
oxacillin, nafcillin, dicloxacillin- because of altered PBP
20
Q
Toxicity caused by narrow spectrum penicillins
A
oxacillin, nafcillin, dicloxacillin - - hypersensitivity reactions- - interstitial nephritis
21
Q
What is the use of nafcillin
A
naf for staph
22
Q
Name wide spectrum penicillins
A
ampicillin, amoxicillin (aminopenicillins)
23
Q
Mechanism of wide spectrum penicillins
A
ampicillin, amoxicillin - same as penicillin- binds PBP, block transpeptidases cross-linking peptidoglycans
24
Q
Difference between narrow and wide spectrum penicillins
A
ampicillin, amoxicillin vs nafcillin, oxacillin, dicloxacillin - wide spectrum are penicillinase sensitive whereas narrow spectrum are penicillinase resistant
25
What are wide spectrum penicillins commonly combined with and why
ampicillin, amoxicillin -clavulanic acid to protect against beta lactamase
26
What is the difference between amoxicillin and ampicillin
amoxicillin has more oral bioavailability than ampicillin
27
what are the uses for wide spectrum penicillins
Haemophilus influenzae;E. coli;Listeria monocytogenes; Proteus mirabilis; Salmonella; Shigella; enterococci; "ampicillin/amoxicillin HELPSS kill enterococci"
28
toxicity caused by wide spectrum penicillins
hypersensitivity, ampicillin rash, pseudomembranous colitis
29
resistance to wide spectrum penicillins caused by
beta lactamases cleave beta lactam ring
30
Name extended spectrum penicillins
ticarcillin, piperacillin
31
what is the mechanism of extended spectrum penicillins
Ticarcillin, piperacillin - same as penicillin (bind PBP, block transpeptidases cross-linking peptidoglycan)
32
use of extended spectrum penicillins
ticarcillin, piperacillin - antipseudomonal (Pseudomonas spp.) - gram (-) rods
33
limitations of extended spectrum penicillins
susceptible to penicillinase, so use with clavulanic acid
34
toxicity to extended spectrum penicillins
hypersensitivity
35
name beta lactamase inhibitors
#NAME?
36
use of beta lactamase inhibitors
often used with penicillins to protect the antibiotic from destruction by beta lactamase (penicillinase)
37
Cephalosporins -- mechanism
beta lactam drug that inhibits cell wall synthesis but are less susceptible to penicillinases
38
are cephalosporins bactericidal or bacteristatic
#NAME?
39
name first generation cephalosporins
cefazolin, cephalexin
40
1st gen cephalosporins -- use
cefazolin, cephalexin - gram (+) cocci - Proteus mirabilis - E. coli - Klebsiella pneumoniae - "PEcK"
41
common use of cefazolin
used prior to surgery to prevent S. aureus infection
42
2nd gen cephalosporins -- names
cefoxitin, cefaclor, cefuroxime
43
2nd gen cephalosporins -- use
cefoxitin, cefaclor, cefuroxime- gram (+) cocci- Haemophilus influenzae- Enterobacter aerogenes- Neisseria spp.- Proteus mirabilis- E. coli- Klebsiella pneumoniae- Serratia- "HEN PEcKS"
44
3rd gen cephalosporins -- names
ceftriaxone, cefotaxime, ceftazidime
45
3rd gen cephalosporins -- use
ceftriaxone, cefotaxime, ceftazidime - serious gram (-) infections resistant to other beta lactams
46
Use of ceftriaxone
meningitis and gonorrhea
47
use of ceftazidime
pseudomonas
48
4th gen cephalosporins -- name
cefepime
49
4th gen cephalosporins -- use
increased activity vs Pseudomonas and gram (+) organism
50
Name organisms typically not covered by cephalosporins + exception
LAME - Listeria - Atypicals (chlamydia, mycoplasma) - MRSA - Enterococci ; Exception: Ceftaroline covers MRSA
51
What is ceftaroline
the first "5th generation" cephalosporin
52
ceftaroline -- use
broader Gram-positive spectrum of activity than all other cephalosporins
53
cephalosporin -- toxicity
#NAME?
54
Aztreonam -- mechanism
prevents peptidoglycan crosslinking by binding to PBP3
55
Aztreonam -- characteristics
#NAME?
56
Aztreonam -- use in infection with
- gram (-) rods ONLY - no activity against gram (+) or anaerobes
57
Aztreonam -- indicated for patients who
#NAME?
58
Carbapenems -- names
imipenem, cilastatin, meropenem
59
Imipenem -- characteristics
broad-spectrum, beta-lactamase resistant carbapenem
60
Cilastatin -- mechanism
inhibitor of renal dehydropeptidase I
61
Imipenem -- restrictions
must always be administered with cilastatin to decrease inactivation of drug in renal tubules
62
name newer carbapenems
ertapenem, doripenem
63
carbapenem -- uses
- gram (+) cocci - gram (-) rods - anaerobes
64
carbapenem -- side effects
GI distress, skin rash, CNS toxicity (seizures) at high plasma levels
65
Carbapenems -- limitations
wide spectrum but significant side effects limit use to life-threatening infections or after other drugs have failed
66
Carbapenems -- which drug is exception to which limitations
meropenem has reduced risk of seizures and is stable to dehydropeptidase I
67
Vancomycin - mechanism
inhibits cell wall peptidoglycan formation by binding D-ala D-ala portion of cell wall precursors. is bactericidal
68
Vancomycin -- use
- Gram (+) only - serious multidrug resistant organisms including MRSA, enterococci and C.diff (oral dose for pseudomembranous colitis)
69
Vancomycin -- toxicity
Red man syndrome -- nephrotoxicity, ototoxicity, thrombophlebitis, diffuse flushing - well tollerated in general -- does NOT have many problems
70
what can prevent red man syndrome
pretreating with antihistamines and slow infusion rate
71
What causes Vancomycin resistance
amino acid change of D-ala D-ala to D-ala D-lac
72
protein synthesis inhibitors -- mechanism
specifically target smaller bacterial ribosomes (70S made of 30S and 50S) leaving human 80S ribososmes alone
73
Name 30S inhibitors and whether bactericidal or static
Aminoglycosides - cidal ; Tetracyclines - static
74
Name 50S inhibitors and whether static or cidal
Chloramphenicol - static ; Clindamycin - static; Erythromycin (macrolides) - static ; Linezolid - variable ; "buy AT 30, CCEL at 50"
75
additional mechanism of aminoglycosides
causes misreading of mRNA
76
Aminoglycosides -- names
Gentamicin, Neomycin, Amikacin, Tobramycin, Streptomycin
77
Aminoglycosides -- mechanism
gentamycin, neomycin, amikacin, tobramycin, streptomycin - bactericidal, - inhibit formation of initiation complex - cause misreading of mRNA - Block translocation
78
Aminoglycosides -- limitations
require O2 so ineffective against anaerobes (aminO2glycosides)
79
Aminoglycosides -- use
gentamycin, neomycin, amikacin, tobramycin, streptomycin - gram (-) rod infections
80
What are aminoglycosides used with
synergistic with beta-lactams
81
Neomycin -- use
bowel surgery
82
Aminoglycosides -- toxicity
Gentamycin, Neomycin, Tobramycin, Amikacin, Streptomycin - nephrotoxicity - neuromuscular blokade - ototoxicity - teratogen
83
Aminoglycosides -- what increases likelihood of nephrotoxicity
when used with cephalosporins
84
Aminoglycosides -- what increases likelihood of ototoxicity
when used with loop diuretics
85
Aminoglycosides -- resistance caused by
transferase enzymes that inactivate the drug by acetylation, phosphorylation or adenylation
86
Tetracyclines -- names
tetracycline, doxycycline, demeclocycline, minocycline
87
demeclocycline -- mechanism and use
ADH antagonist, acts as diuretic in SIAdh
88
Tetracyclines -- mechanism
tetracycline, doxycycline, demeclocycline, minocycline - bacteriostatic - binds 30S and prevents attachment of aminoacyl-tRNA
89
Tetracycilnes -- limitations
#NAME?
90
Doxycycline -- limitation
fecally elimitinated and cannot be used in patients with renal failure
91
Tetracycines -- use
#NAME?
92
why are tetracyclines particularly helpful in rickettsia and chlamydia
it can accumulate intracellularly thus helpful for intracellular bugs
93
Tetracycline -- toxicity
#NAME?
94
Tetracycline -- contraindication
pregnancy
95
Tetracycline -- resistance caused by
decreased uptake into cell or increased efflux out of cell caused by plasmid-encoded transport pumps
96
Macrolides -- names
azythromycin, clarithromycin, erythromycin
97
Macrolides -- mechanism
azythromycin, clarithromycin, erythromycin - inhibit protein synthesis by blocking translocation - binds 23S rRNA of the 50S subunit - bacteriostatic
98
Macrolides -- use
Azythromycin, clarithromycin, erythromycin - atypical pneumonias (mycoplasma, chamydia, legionella) - STDs (Chlamydia) - Gram (+) cocci (strep infections in patients allergic to penicillin)
99
Macrolides -- toxicity
MACRO; - Motility issues - Arrhythmia caused by prolonged QT - Cholestatic hepatitis (acute) - Rash - eOsinophilia
100
Macrolides -- drug interactions
increase serum concentration of theophyllines, oral anticoags
101
Macrolides -- indication
pregnant women ; "macrolides for pregnant wives"
102
Macrolides -- resistance caused by
methylation of 23S rRNA binding site
103
Chloramphenicol -- mechanism
block peptidyltransferase at 50S ribosomal subunit ; - bacteriostatic
104
Chloramphenicol -- use
meningitis caused by - H. influenzae - neisseria meningitides - Strep. pneumoniae
105
Chloramphenicol -- toxicity
- Anemia (dose dependent) - aplastic anemia (dose independent) - Gray baby syndrome (in premature infants because they lack liver UDP-glucuronyl transferase)
106
Chloramphenicol -- resistance
#NAME?
107
Clindamycin -- mechanism
- blocks peptide transfer (transpeptidation) at 50S ribosomal subunit - bacteriostatic
108
Clindamycin -- use
#NAME?
109
Clindamycin vs metronidazole
note!! treats anaerobes above the diaphragm vs. metronidazole which treats anaerobic infections below the diaphragm
110
Clindamycin -- toxicity
pseudomembranous colitis (C.difficile overgrowth), fever diarrhea
111
Sulfonamides -- names
sulfamethoxazole (SMX), sulfisoxazole, sulfadiazine
112
Sulfonamides -- mechanism
#NAME?
113
Sulfonamides -- use
- gram (+) - gram (-) - Nocardia - Chlamydia
114
Sulfonamides -- how to treat UTI
triple sulfas or SMX for simple UTI
115
Sulfonamides -- toxicity
#NAME?
116
Sulfonamides -- drug interactions
- displace other drugs from albumin (eg. warfarin)!!!
117
Sulfonamides -- resistance
#NAME?
118
Trimethoprim -- mechanism
inhibits bacterial dihydrofolate reductase - bacteriostatic
119
trimethoprim -- use + combos
- combined with sulfonamides (trimethoprim-sulfamethoxazole [TMP-SMX]) - cause sequential sequential block of folate synthesis - combo used for UTIs, Shigella, Salmonella, Pneumocystis jirovecci pneumonia (Rx and PPx)
120
Fluoroquinolones -- names
#NAME?
121
Quinolones -- name
nalidixic acid
122
Fluoroquinolones -- mechanism
#NAME?
123
Fluoroquinolones -- contraindications
#NAME?
124
fluoroquinolones -- use
- gram (-) rods of urinary and GI tracts (includes pseudomonas) - Neisseria - some gram (+)
125
Fluoroquinolones -- toxicity
- GI upset, superinfections, skin rashes, headache, dizziness - less commonly: cause tendonitis, tendon rupture, leg cramps, myalgias - prolonged QT interval - tendon rupture in people >60 years and in people using prednisone-- "fluoroquinoLONES hurt attachments in your BONES"
126
Fluoroquinolones -- resistance caused by
#NAME?
127
Metronidazole -- mechanism
forms free radical toxic metabolites in the bacterial cell that damage DNA. - bactericidal - antiprotozoal
128
Metronidazole -- use
treats: - Giardia - Entamoeba - Trichomonas - Gardnerella vaginalis - Anaerobes (bacteroides, C. difficult) -h.Pylori (if used with PPI and clarythromycin for thriple therapy)-- "GET GAP on the Metro with Metronidazole!"
129
Metronidazole vs Clindamycin
metronidazole treats anaerobic infections below the diaphragm vs. clindamycin (anaerobic infections above the diaphragm)
130
metronidazole -- toxicity
disulfiram-like rxn with alcohol -- headache -- metalic taste
