Micriobio: Therapy Flashcards
1
Q
what is penicillin G
A
this is a first generation classic lactam antibiotic. it is beta lactam sensitive
2
Q
what does penicillin G treat
A
mostly used for gram positive organisms like S pneumonia, s pyogenes. commonly used in T pallidum (syphillis)
3
Q
toxicity of penicillin G
A
hemolytic anemia and hypersensitivity reaction
4
Q
how does resistance develop to penicillin G
A
penicillinase (beta lactamase)
5
Q
what are ampicillin and amoxicillin
A
2nd generation penicillins. still sensative to beta lactamase. greater spectrum of use.
6
Q
bugs that 2nd generation penicillins can kill
A
HELPSS kill enterococci H influenza E coli Listeria monocytogenes Proteus mirabilis Salmonella Shigella
7
Q
toxicity of 2nd generation penicillins
A
HS reaction, rash, and pseudomembranous colitis.
8
Q
what is the one bug that 3rd generation penicillins treat
A
S aereus (really only nafcillin)
9
Q
what are examples of 3rd generation penicillins
A
oxacillin, nafcillin, dicloxacillin
10
Q
what is different about 3rd generation penicillins
A
they have beta lactam resistance by having a very very bulky R group. this limits their action those.
11
Q
strange side effect from 3rd generation penicillins
A
interstitial nephritis
12
Q
what is special about 4th generation penicillins
A
they treat psuedomonas (and gram negative rods)
13
Q
examples of 4th generation penicillins
A
ticarcillin, piperacillin
14
Q
beta lactamase inhibitors
A
CAST
Clavulonic Acid
Sulbactam
Tazobactam.
15
Q
how do cephalosporins kill bacteria
A
same way penicillins do! they bind to penicilin binding protein (PBP) and block transpeptidase cross linking of peptidoglycan
16
Q
what generation cephalosporin are cefazolin and cephalexin?
A
first generation
17
Q
what are cephalexin and cefazolin used for?
A
gram positive cocci. PEcK:
Proteus miribalis
E Coli
Klebsiella pneumoniae
18
Q
what is cefazolin specifically used for
A
surgical prophylaxis against S aureus infections
19
Q
what generation cephalosporin are cefoxitin, cefaclor, cefuroxime?
A
2nd generation
20
Q
what do second generation cephalosporins treat
A
gram positive cocci infections like H influenza, Enterobacter, Neisseria, Proteus, Ecoli Klebsiella,
Serratia
21
Q
what generation cephalosporins are ceftriaxone, cefotaxime, ceftazidime
A
3rd generation
22
Q
what do you use 3rd generation cephalosporins for
A
gram negative infections that are resistant to other beta lactams
23
Q
what is special about ceftriaxone?
A
often used to treat meningitis
24
Q
which 3rd generation cephalosporin cannot be used to treat meningitis
A
cefoperazone. does not cross the BBB
25
which cephalosporin (3rd gen) is good for pseudomonas
ceftazidime
26
what is cefepime?
4th generation cephalosporin
27
what are 4th generation cephalosporins good for?
increased activity against pseudomonas and gram positive organisms
28
what is ceftaroline?
5th generation cephalosporin
29
what are 5th generation cephalosporins good for?
very broad coverage. covers gram positive and gram negative organisms including MRSA but NOT pseudomonas.
30
toxicity from cephalosporins?
vitamin K deficiency, low cross reactivity with penicillin, increases nephrotoxicity of aminoglycosides
31
what is aztreonam used for
gram negative rods. usually pseudomonas.
32
why is aztreonam's status as a monobactam important
no cross reactivity in pen allergic patients.
33
how does aztreonam work?
binds specifically to PBP3.
34
toxicity of aztreonam
basically none. very well tolerated. maybe some GI upset
35
what kind of drug ends in "penem"
any of the carbapenems like imipenem and meropenem
36
what is important to remember about imipenem
it must be given with cilastatin (inhibition of renal dehydropeptidase I) to decrease inactivation of the drug in the renal tubules. "the kill is lastin with cilastin"
37
are the carbepenems resistant to beta lactamase
yes
38
what do the carbepenems function against?
gram positive cocci, gram negative rods and anerobes.
39
do we use the carbepenem drugs often?
no because life threatening side effects. only use in serious infections.
40
major toxocity associated with imipenem
seizures
41
newer carbepenems
ertapenem and doripenem. have increased pseudomonas coverage
42
vancomycin mechanism
inhibits cell wall peptidoglycan formation by binding to d-ala d-ala portion of the cell wall. bacteriocidal.
43
what do we use vancomycin for?
gram positive organisms only- serious multi drug resistant organisms only. includes MRSA, enterococci, and C diff (oral dose)
44
which drug is red man syndrome associated with?
Vancomycin- red man syndrome- can be prevented with anti histamines and slow infusion rate
45
other toxic effects of vancomycin
NOT: nephrotoxicity, ototoxicity, Thrombophlebitis (vein inflammation associated with a clot)
46
resistance to vanco
bacteria modify their amino acid sequence from D ala-D ala to D ala Dlactose.
47
which two drugs inhibit the 30 S subunit
Aminoglycosides and Tetracyclines
48
which drugs inhibit the 50S subunit
chloramphenicol, clindamycin (bacteriostatic)
Macrolides (erythromycin for ex)
Linezolid
49
which 2 drugs target the initiation complex
aminoglycosides and linezolid
50
which drugs inhibit the elongation (the A site)?
tetracyclines and dalfopristin
51
which drug inhibits the peptidyl transferase enzyme
chloramphenicol
52
which drugs inhibit translocation of the ribosome
macrolides and clindamycin
53
gentamicin, neomycin, amikacin, tobramycin and streptomycin are what kind of drug
aminoglycoside
54
mechanism of aminoglycosides
cause misreading of mRNA and block translocation.
55
what is unique about uptake into the cell of aminoglycosies
require oxygen
56
are aminoglycosides bacteriostatis or cidal?
bacteriocidal
57
clinical use of amionglycosides
severe gram negative rod infections. neomycin for bowel surgery. can be used against pseudomonas
58
toxic side effects of aminoglycosides
nephrotoxic (especially when used with a cephalosporin),
neuromuscular blockage- blocks ach release
ototoxicity (especially when used with loop diuretics)
teratogen
59
resistance to amninoglycosides
bacteria produced enzymes that inactivate the drug by acetylation, phosphorylation or adenylation
60
what class of drugs do: tetracyclin, doxycycline and minocycline belong to?
tetracyclines.
61
cyclin drugs are...
tetracycline group. blocks the elongation so it cannot put a tRNA into the A group
62
why is doxycycline different?
eliminated via liver and colon so it can be used in patients with renal disease
63
what inhibits all tetracycline absorption in the gut?
any divalent cations like Ca2+ or Mg2+ or iron containing things. do not take with these.
64
what are tetracyclines used for?
can accumulate in the cell and makes them effective against things like ricketssia, chlamydia etc. also can be used to treat acne
65
what are side effects of tetracyclines?
discoloration of the teeth, inhibition of bone growth in children, photosensitivity
66
resistance to tetracyclines
bacteria has pumps that it uses to pump the drug out. pumps are plasmid encoded.
67
azithromycin, clarithromycin and erythromycin- what class of drug do these belong to?
macrolides. prevent translocation. bind to the 23S rRNA of the 50S ribosomal subunit. bacteriostatic.
68
what do we use macrolides for?
atypical pneumonia (mycoplasma, chlamydia, legionella), STDs (chlamydia) and gram positive cocci
69
what is the really important bug that macrolides kill that boards love to ask about?
legionella pneumophilia
70
toxicity of macrolides
activate motilin receptors increasing GI movement, reversible deafness, rash, arrythmias from prolonged QT intervals, cholestatic hepatitis, eosinphilia.
can increase serum concentration of theophyllines, oral anticoagulants.
71
drug resistance to macrolides
methylation of the 23S rRNA binding site so the drug can't bind
72
chloramphenicol
blocks peptidyltransferase function at the 50S ribosome. bacteriostatic
73
chloramphenicol uses
meningitis (H influenza, N meningitidis, S pneumonia) and Rocky mountain spotted fever
74
do we use chloramphenical in the US
no because of toxicity. very rare.
75
toxicity of chloramphenical
anemia, aplastic anemia, gray baby syndrome in premature infants (see blue lips and blue baby because they lack the UDP glucuronyl transferase).
76
resistance to chloramphenical
plasmid encoded acetyltransferase inactivates the drug
77
mechanism of clindamycin
this is not a macrolide! it is similar though. it blocks translocation at 50s unit. bacteriostatic.
78
function of clindamycin
treats anerobes above the diaphragm (metronidazole treats below the diaphragm). things like bacteirodes, C perfringes, aspiration pneumonia, lung abscess, oral infections. also treats Group A strep.
79
toxicity from clindamycin
pseudomembranous colitis, fever, diarrhea
80
drugs that end in "Zole" or have sulfa in them are...
sulfonamides.
81
what enzyme do the sulfonamides inhibit?
dihydropteroate synthase
82
what is the mecanism of sulfonamides
inhibit folate production which is necessary for bacteria
83
what disease should you test for before giving sulfonamides?
G6PD deficiency
84
toxicity of sulfonamides
hemolysis if G6PD, nephrotoxicity, photosensitivity, kernicterus, displace other drugs like warfarin from alubmin. likes to bind proteins!!!
85
how can bacteria build resistance to sulfonamides
alter the dihydropteroate synthase enzyme or increase PABA
86
what enzyme does trimethoprim inhibit
dihydrofolate reductase.
87
what drug is trimethroprim commonly used with?
sulfamethoxazole- making the TMP-SMX combination
88
what do you use TMP-SMX to treat?
UTIs, shigella, salmonella, pneumocytis jirovecii pneuumonia and prophalaxis, toxoplasmosis prophylaxis
89
toxicity of trimethroprim
megaloblastic anemia, bone marrow supression
90
what drugs end in "floxacin"...
floroquinolines.
91
mechanism of floroquinolones
inhibit DNA gyrase (DNA topoisomerase II IV).
92
what drug should you not take floroquinolones with?
antacids
93
use of floroquinolones?
gram negative rods like pseudomonas, neisseria, soma gram positives.
94
what does bacterial topoisomerase II do?
prevents supercoiling of bacteria so it can replicate the DNA
95
what does bacterial topoisomerase IV do?
prevents sister chromatids from twisting. helps with G2 and mitosis phase.
96
unique toxicity of floroquinolones
tendonitis, tendon rupture, increased QT interval, photosensitivity.
97
why should you not use floroquinolones in pregnant women?
they have development issues with the cartilage.
98
resistance to floroquinolones
chromosome encoded mutation in DNA gyrase, plasmid mediated resistance, efflux pumps.
99
drug that prevents the introduction of negative super coils
quinolones!
100
metronidazole mechanism
forms free radical toxic metabolites in the bacterial cell that damages DNA
101
what do we use metronidazole to treat?
Giardia, Entameoba, Trichomonas, Gardenella vaginalis. can be used with a PPI to treat H pylori (and clarithromycin).
102
what does metronidazole have to do with the diaphragm
we usually say it is used to treat infections below the diaphragm. clindamycin is used to treat infections above the diaphragm (anaerbic).
103
unique metronidazole toxicities
disulfram like reaction and metallic taste.
104
pneumonic for drugs to treat TB
RIPE: rifampin, isoniazid, pyrazinamide, ethambutol.
105
how to prophylaxis against TB
isoniazid
106
M avium intracellularae prophylaxis
Azithromycin, rifabutin
107
drugs to treat M avium intracellurae
actually more resistant than TB itself. use azithromycin, clarithromycin, ethambutol as a minimum
108
how to treat mycobacterium leprae infection
dapsone and rifampin for tuberculoid form.
109
what drug do you use to treat lepromatous leprosy form?
dapsone, rifampin, clofazimine
110
INH mechanism
decrease mycolic acid production.
111
what does INH need to work?
bacterial catalase peroxidase (encoded by KatG) needed to convert INH to active drug
112
toxicity from INH
neurotoxicity, hepatotoxicity, B6 deficiency, lupus
113
what are both rifampin and rifabutin
rifamycins
114
mechanism of rifamycins
inhibits DNA dependent RNA polymerase
115
what do you use rifampin for
TB, leprosy, meningococcal prophylaxis and in close contacts (kids) with H influenza type B.
116
toxicity of rifampin
increases P450, orange body fluids,
117
in HIV patient, do you prefer rifampin or rifabutin?
rifabutin bc less increase in P450.
118
pyrazinamide mechanism
unknown. thought to acidify intracellular envrionment via conversion to pyrazinoic acid. effective in acidic pH of phagolysosomes, where TB engulfed by macrophages is found.
119
toxicity of pyrazinamide
hyperuricemia
120
ethambutol mehcanism
blocks arabinosyltransferase which is necessary for carbohydrate polymerization of mycobacterium cell wall.
121
unique toxicity of ethambutol
optic neuropathy- red green color blindness
122
what do we give people to prevent endocarditis from surgical or dental procedures
penicillins
123
what do we give people to prevent gonorrhea
ceftriaxone
124
what do we give those with recurrent UTI infections
TMP/SMX
125
what to give to prevent meningococcal infection
ciprofloxin for adults, rifampin for children
126
what do we give pregnant women carrying group B strep?
ampicillin
127
what do we give to prevent gonoccocal or chlamydia conjunctivitis in a newborn
erythromycin ointment.
128
how to prevent post surgical infections with S aureus
Cefazolin
129
prophylaxis of strep in a kid with prior rheumatic fever
oral penicillin
130
how to prevent syphillis
Benzathine penicillin G
131
prophylaxis when CD4<200 in HIV patient
TMP-SMX for pneumocystis pneumonia
132
prophylaxis when CD4<100 in HIV patient
TMP-SMX for pneumocystic pneumonia and toxoplasmosis
133
prophylaxis when CD4<50 in HIV patient
Azithromycin for mycobacterium avium complex
134
how to treat MRSA
vanco, daptomycin, linezolid (can cause seratonin syndrome), cetaroline
135
how to treat VRE
linezolid and streptogrammins
136
mechanism of Amphotericin B
binds to ergosterol forms membrane pores and leaks electrolytes
137
what does amphotericin B treat
serious systemic mycoses. can be combined with flucytosine for cryptococcoal meningitis. can be given intrathecally for fungal meningitis.
138
what do you need to supplement with amphotericin B
K+ and Mg2+ because of altered renal tubule permeability
139
toxic effects of amphotericin B
nephrotoxic, arrythmias, anemia, IV phlebitis, . hydration and liposomal amphotericin decrease toxicity
140
nystatin
this is the topical form of amphotericin B. too strong for systemic use
141
classic clinical use for nystatin
"swish and swallow".. for oral candidiasis. topical for diaper rash and vaginal candidiasis
142
azole mechanism
inhibit ergosterol synthesis by inhibiting the 14 alpha demethylase enzyme.
143
what are azoles used for?
can be used for cryptococcal minigitis in AIDS patients and any other infections.
144
treatment for blastomyces, coccidoides, histoplasma
Intraconazole
145
topical fungal infection treatment
clotrimazole and miconazole
146
toxicity of azoles
testosterone synthesis inhibition- gynecomastia, especially common with ketoconazole. can get liver issues, inhibits P450
147
flucytosine mechanism
inhibits DNA and RNA biosynthesis by conversion of 5FU to cytosine deaminase. it is incorporated into the fungal RNA once three phosphates are added. also forms 5Fd-UMP which inhibits thymine production.
therefore blocks gene expression and DNA replication
148
use of flucytosine
especially with amphotericin B in cryptococcal meningitis.
149
toxicity of flucytosine
bone marrow supression
150
caspofungin, micafungin, etc.
are all echinocandins
151
mechanism of echinocandins
inhibits cell wall synthesis by inhibiting synthesis of beta glucan.
152
clinical use of echinocandins
invasive aspergillosis and candida
153
toxicity of echinocandins
flushing -increased histamine
154
Terbinafine
inhibits the fungal enzyme squalene expoxidase, which is the first enzyme in ergosterol production.
155
clinical use of terbinafine
dermatophytes- especially of the nails
156
griseofulvin mechanism
interferes with microtubule formation and disrupts mitosis. deposits in the keratin containing tissues so it stays on the skin and nails.
157
clinical uses of griseofulvin
oral treatment of superficial infections. inhibits growth of dermatophytes.
158
toxicity of griseofulvin
teratogenic, carcinogenic, condusion, increase P450 and warfarin metabolism
159
what does pyrimethamine treat
toxoplasmosis
160
what do suramin and melarsoprol treat
Trypanosome brucei
161
what does nifurtimox treat?
T. cruzi
162
what does sodium stibogluconate treat?
leishmaniasis
163
chloroquine mechanism
this blocks detoxification of heme into hemozoin. heme accumualtes and is toxic to plasmodium.
164
chloroquine clinical use
plasmodium other than falciporum bc resistance is too high. resistance comes from membrane pumps to decrease intracelular concentration of the drug.
165
how to treat malaria
artemether/lumefantrine or atovaquone/proguanil.
166
how to treat life threatening malaria in US
quinidine or artesunate
167
praziquantel
should be used to treat flukes (trematodes) like shistosoma
