25 - Antibacterial drugs Flashcards
1
Q
Term: antibacterial that can eradicate an infection in the absence of host defense mechanisms
A
bactericidal
2
Q
Term: antibacterial that can inhibit microbial growth but requires host defense mechanisms to eradicate the infection
A
bacteriostatic
3
Q
Enumerate: Bactericidial Antibiotics
A
- Vancomycin
- Fluoroquinolones
- Penicillins
- Aminoglycosides
- Metronidazole
Very Finely Proficient At Murder
4
Q
Enumerate: Bacteriostatic antibiotics
A
- Erythromycin
- Sulfamethoxazole
- Trimethoprim
- Tetracycline
- Clindamycin
- Chloramphenicol
ESTTCC (static!)
5
Q
Term: lowest concentration of antimicrobial drug capable of inhibiting growth of an organism in a defined growth medium
A
Minimum Inhibitory Concentration
6
Q
Term: initiation of drug treatment before identification of a specific pathogen
A
Empiric therapy
7
Q
Term: use of an antimicrobial drug to decrease the risk of infection
A
Antibiotic prophylaxis
8
Q
DOC for MRSA
A
Vancomycin
9
Q
DOC for VRSA
A
Linezolid
10
Q
Enumerate: Drug classes of Beta-Lactam Antibiotics
A
- Penicillins
- Cephalosporins
- Monobactams
- Carbapenems
11
Q
MOA of Beta-lactam anitbiotics:
A
- binds to penicillin-binding proteins
- inhibits the transpeptidation reaction, disrupting cell wall synthesis
12
Q
DOC for syphillis
A
Penicillin G
13
Q
Common adverse reactions to Penicillin (give 3)
A
- Hypersensitivity
- cross-reactivity with other penicillins
- gastrointestinal disturbance
14
Q
Enumerate: (2) long-acting preparations of Penicillin G
A
- Benzathine Penicillin
- Procaine Penicillin
15
Q
- Give example of extended spectrum Penicillin
- Enumerate: bacteria covered by extended spectrum penicillins.
A
-Ampicillin
- Haemophilus influenza
- Escherichia coli
- Listeria monocytogenes
- Proteus mirabilis
- Salmonella
- enterococci
HELPSe
16
Q
Enumerate: anti-pseudomonal Penicillins
A
- Ticarcillin
- Carbenicillin
- Piperacillin
Takes Care of Pseudomonas
17
Q
Drug of choice for Acute Rheumatic Fever:
A
Penicillin G
18
Q
Drug of choice for Streptococcus agalactiae:
A
Penicillin G
19
Q
Treatment for Group D streptococcus:
A
Penicillin + gentamicin
20
Q
DOC for Streptococcus pneumoniae
A
Penicillin G
21
Q
DOC for cutaneous anthrax
A
Ciprofloxacin
22
Q
DOC for pseudomembranous colitis
A
metronidazole
23
Q
DOC for pertussis
A
Erythromycin
24
Q
treatment for cholera:
A
Tetracycline or azithromycin
25
Drug that is given as prophylaxis before GI surgeries:
cefoxitin
26
DOC for early Lyme disease
doxycycline
Lyme = Borrelia burgdorferi = Ixodes = i-XO-des = d-OX-ycycline!!!!!
27
DOC for all rickettsial infections:
doxycycline
28
Why is cilastatin given together with imipenem?
Cilastatin inhibits renal metabolism of imipenem by dihydropeptidase
29
This class of beta-lactam drugs is reserved for serious, life-threatening infections:
Carbapenems
30
Drug class of Aztreonam
Monobactam
31
This drug has no cross-allergenicity with penicillins, and does not cause hypersensitivity
Aztreonam
32
Enumerate (3): beta-lactams and beta-lactamase inhibitor pairs
- Piperacillin-Tazobactam (Pip-Tazo)
- Amoxicillin-Clavulanic acid (Co-amoxiclav)
- Ampicillin-Sulbactam (Ampi-Sul)
33
Drug class of Vancomycin:
glycopeptide
34
MOA of Vancomycin:
Inhibits cell wall synthesis by binding to D-ala-D-ala terminus, inhibiting transglycosylation, inhibiting elongation and cross-linking of the peptidoglycan chain
35
- Adverse effect of Vancomycin:
| - How to avoid this adverse effect?
- Redman syndrome
| - slow down infusion rate
36
Formulation of Vancomycin that can be used in the treatment of pseudomembranous colitis:
oral Vancomycin
37
Enumerate: drugs of last resort
- Imipenem
- Amikacin
- Meropenem
- Linezolid
- Streptogramins
- Vancomycin
I AM your Last Shot at Victory
38
MOA of Bacitracin
Interferes with a late stage in cell wall synthesis in gram-positive organisms
39
Adverse effect of bacitracin:
nephotoxicity (thus only used topically)
40
MOA of Cycloserine
blocks incorporation of D-Ala into the pentapeptide side chain of the peptidoglycan
41
uses of Cycloserine (1)
2nd line drug for drug-resistant tuberculosis
42
MOA of Daptomycin
binds to cell membrane causing depolarization and rapid cell death
43
- Adverse effect of Daptomycin
| - how to monitor this adverse effect?
- Myopathy
| - serial monitoring of creatine phosphokinase
44
- MOA of fosfomycin
| - uses?
- prevents formation of NAM
| - uncomplicated UTI
45
Enumerate: 30S ribosomal subunit inhibitors:
- Aminoglycosides
- Tetracyclines
AT CELLS
46
Enumerate: 50S ribosomal subunit inhibitors:
- Chloramphenicol
- Erythromycin and other macrolides
- Lincosamides (Clindamycin)
- Linezolid
- Streptogramins
AT CELLS
47
- Enumerate: protein synthesis inhibitors that are bactericidal
- Enumerate: protein synthesis inhibitors that are bacteriostatic
- cidal: Aminoglycosides, Streptogramin
| - static: all the rest - Tetracycline, Chloramphenicol, Erythromycin, Lincosamide (Clindamycin), Linezolid
48
Prominent adverse effect of chloramphenicol:
gray baby syndrome
49
Most potent tetracycline:
minocycline
50
tetracycline with the broadest spectrum:
tigecycline
51
Adverse effect of tetracyclines:
tooth enamel discoloration/dysplasia
52
Enumerate: 3 examples of macrolides:
- Erythromycin
- Azithromycin
- Clarithromycin
53
All macrolides inhibit CYP450 except:
Azithromycin
54
General indication for use of macrolides:
useful as alternative for those allergic to penicillins
55
Enumerate: Adverse effect of macrolides (2)
- GI upset
| - QT prolongation
56
Drug class of Clindamycin:
Lincosamide
57
Adverse effect of Clindamycin
-Pseudomembranous colitis (Clostridium difficile growth)
58
Differentiate Clindamycin vs Metronidazole in terms of usage:
- Clindamycin - used for anaerobic infections above the diaphragm
- Metronidazole - used for anaerobic infections below the diaphragm
59
Representative drug for Streptogramin:
Quinupristin-Dalfopristin
60
- Enumerate: Two modes of antibacterial action:
| - give examples of drugs that exhibit these modes:
1. concentration-dependent killing action - e.g. aminoglycosides
2. time-dependent killing action - e.g. penicillins, cephalosporins
61
- What is Post-Antibiotic effect?
| - What classes of drugs exhibit this effect?
- killing action continues even when the drug levels in the plasma have declined below measurable levels
- e.g. aminoglycosides, quinolones
62
Identify: Aminoglycoside with the narrowest spectrum
Amikacin
63
- What class of drugs have a synergistic effect with aminoglycosides?
- explain mechanism of this synergism
- classic drug combination that utilizes this synergism:
- cell wall synthesis inhibitors
- they enhance the uptake of aminoglycosides into the cell
e.g. Ampicillin+Amikacin
64
- Enumerate: (6) examples of aminoglycosides
| - Enumerate: (3) adverse effects of aminoglycosides
- Gentamicin
- Neomycin
- Amikacin
- Tobramycin
- Streptomycin
- Spectinomycin
- Nephrotoxicity
- Ototoxicity
- Teratogen
GNATSS NOT!
65
Enumerate: (2) most ototoxic aminoglycosides:
amikacin, kanamycin
66
Identify: Aminoglycoside with the least resistance
Amikacin
67
Treatment for Yersinia pestis:
Streptomycin
68
Why is neomycin limited to topical and oral use only? (adverse effect)
because it can cause hepatic encephalopathy
69
Use of spectinomycin:
Drug-resistant Neisseria gonorrhoeae or for patient allergic to penicillins
70
Treatment of Neisseria gonorrhoeae
ceftriaxone + doxycycline
71
Enumerate: (2) most vestibulotoxic aminoglycosides:
tobramycin, gentamicin
72
Enumerate: (2) most nephrotoxic aminoglycosides:
tobramycin, gentamicin
73
adverse effect of spectinomycin:
non-depolarizing NMJ blockade
74
- MOA of fusidic acid
| - uses of fusidic acid
- inhibits translocation during protein synthesis
| - topical antimicrobial against common skin pathogens, e.g. Staphylococcus aureus
75
MOA of sulfonamides:
-competitive inhibition of dihydropteroate synthase, inhibiting folic acid synthesis (competes with PABA)
76
MOA of trimethoprim:
-selective inhibitor of dihydrofolate reductase
77
Explain mechanism of synergism of Trimethoprim-Sulfamethoxazole:
- sequential blockade of folate synthesis
| - drug combination is bactericidal
78
Drug class of silver sulfadiazine:
Sulfonamide
79
use of silver sulfadiazine
burn infections
80
Use of trimethoprim-sulfamethoxazole:
- Pneumocystis jirovecii pneumonia
- Nocardia
- UTI
81
Enumerate: adverse effects of sulfonamides:
- SJS/TEN
- GI distress
- granulocytopenia, thrombocytopenia
- crystalluria, hematuria
82
MOA of quinolones: (2)
- inhibit topoisomerase II (DNA gyrase) in gram (-) bacteria
- inhibit topoisomerase IV in gram (+) bacteria
thus inhibiting DNA synthesis
83
- What subset of the population should not be treated with quinolones?
- why?
- patients less than 18 years old
| - may damage growing cartilage and cause arthropathy
84
-Quinolones vs Fluoroquinolones?
- Quinolones: 1st gen
| - Fluoroquinolones: 2-4th gen
85
- example of 1st gen quinolone? (4)
| - uses?
Nalidixic acid, cinoxacin, rosoxacin, oxolinic acid
| UTIs
86
-example of 2nd gen fluoroquinolone? (2)
Ciprofloxacin, ofloxacin
87
-example of 3rd gen fluoroquinolone?
Levofloxacin, moxifloxacin
88
-example of 4th gen fluoroquinolone?
Trovafloxacin
89
Fluoroquinolone with activity agains anaerobic bacteria?
4th gen fluoroquinolones, e.g. Trovafloxacin
90
MOA of metronidazole?
-reactive reduction by ferredoxin forming free radicals that disrupt electron transport chain. Bactericidal.
91
Uses of metronidazole: bacterial (give 4)
- pseudomembranous colitis (Clostridium difficile)
- botulism (Clostridium botulinum)
- bacteroides fragilis
- Gardnerella vaginalis
92
drug class of metronidazole?
nitroimidazole
93
drug class of nitrofurantoin?
nitrofuran
94
MOA of nitrofurantoin?
Forms multiple reactive intermediates when acted upon by bacterial nitrofuran reductase that disrupt protein, RNA, and DNA synthesis
95
Use of nitrofurantoin?
uncomplicated cystitis
96
MOA of mupirocin:
inhibits Staphylococcal isoleucyl tRNA synthetase
97
Uses of mupirocin:
for minor skin infections such as impetigo
98
MOA of isoniazid:
inhibits mycolic acid synthesis, interfering with cell wall synthesis
99
Adverse effects of isoniazid: (2)
hepatotoxicity and neurotoxicity (peripheral)
100
How to prevent neurotoxicity of isoniazid:
co-administer pyridoxine (Vit. B6), 2-4 hours apart
101
MOA of rifampicin
inhibits DNA-dependent RNA polymerase, inhibiting RNA synthesis
102
Adverse effect of rifampicin (2)
orange-colored body fluids
| hepatotoxicity
103
MOA of pyrazinamide:
unknown!
104
adverse effect of pyrazinamide:
hepatotoxicity
105
Enumerate: Hepatotoxic anti-TB drugs: (from least to most hepatotoxic)
Isoniazid < Rifampicin < Pyrazinamide
HRZ!
106
MOA of ethambutol:
inhibits arabinosyl transferases involved in the synthesis of arabinogalactan in mycobacterial cell wall.
107
Identify: bacteriostatic anti-TB drug:
Ethambutol
108
Adverse effect of ethambutol (3):
visual disturbance,
red-green color blindness,
hyperuricemia
109
Uses for streptomycin:
- TB
| - Yesinia pestis
110
MOA of dapsone:
inhibits folic acid synthesis
111
uses of dapsone:
Mycobacterium leprae (most active drug)
112
- drug for dapsone-resistant M. leprae
- MOA:
- adverse effect:
- Clofazimine
- binds to guanine bases in bacterial DNA
- skin discoloration
113
Repository form of dapsone which has drug action that can last for months:
Acedapsone
