Antibiotics I Flashcards
1
Q
recombination
A
incorporate DNA into genome
2
Q
transformation
A
uptake of naked DNA
3
Q
transduction
A
bacteriophage transfer
4
Q
Penicillins
A
Penicillin G/VK Nafcillin/Dicolxacillin Amoxicillin/Ampicillin Amox/clav + Amp/sulbactam Piperacillin Pip/Tazobactam
5
Q
Cephalosporins
A
Cefazolin/Cephalexin
Ceftriaxone
Ceftazdime
6
Q
Carbapenems
A
Imipenem/Cilastin
Meropenem
7
Q
Monobactams
A
Aztreonam
8
Q
Glycopeptide
A
Vancomycin
9
Q
Oxazolidinone
A
Linezolid
10
Q
Cyclic Lipopeptide
A
Daptomycin
11
Q
Macrolide
A
Erythromycin
Clarithromycin
Azithromycin
12
Q
Nitroimidazole
A
Metronidazole
13
Q
Bacteriostatic target
A
protein synth/DNA synth
14
Q
Bacteriostatic Rxs
A
ECSTaTiC Erythromycin (macrolides) Clindamycin Sulfamethoxazole Trimethoprim Tetracyclines Chloramphenicol
15
Q
Bacteriocidal rxs
A
Really Very Fine At Bug Murder Rifampin Vancomycin Fluoroquinolones Aminoglycosides B-lactams Metronidazole
16
Q
Cell wall synthesis inhibitor advantages
A
*selectivity - only bacteria have cell wall
peptidogycan
*only active during synthesis (growing bacteria)
17
Q
what does vancomycin block?
A
cell wall - external phase - strand synthesis
Gucosyltransferase (peptidoglycan synthase)
18
Q
what does penicillin (B lactam) block?
A
- cell wall - strand cross-linking
- Peptidoglycan transpeptidase PBP
- covalent enzyme binding - defective cell wall
19
Q
B lactams select
A
Gram +s, looks like D-ala D-ala to bind peptidoglycan transpeptidase
20
Q
B lactam resistance
Gram -
A
- physical barrier
- mutant porin in outer cell membrane
- efflux pump over all 3 layers
- enzyme inactivation (Gram + AND Gram -) B lactamase
- mutate transpeptidase (PBP-2a not binding B-lact) (Gram + ONLY) (MRSA)
21
Q
Penicillinase resistant bacteria Penicillins
A
Nafcillin (IV) + Dicloxacillin (PO)
22
Q
Extended spectrum (Gram +/-) Penicillins
A
Amoxi (PO), Ampicillin (IV,PO)
23
Q
Extended spectrum anti-pseudomonal Penicillins
A
piperacillin
24
Q
Compounded w/ B-lactamase inhibitor penicillins
A
Amox/clav (PO)
Amp/Sulbactam (IV)
Pip/Tazobactam
25
Penicillin G (IV) + VK (PO)
* susceptible Gram +ves
* Inactivated by gastric acid
* Poor CNS penetration (meningitis)
* Renal secretion - PCT
26
Penicillin G
*bacteria selective - low direct toxicity
27
Penicillin G S.E.
* Superinfection - colitis (acidophilus pills)
* CNS tremors
* Hypersensitivity (rash, anaphylactic, skin TEN)
28
Nafcillin (IV) excretion
biliary (unusual, most pen are kidney)
29
Which acid-stable Pen-resistant pens are orally active?
DICLOXACILLIN
oxacillin
cloxacillin
30
Amoxicillin (extended-spectrum)
acid stable - well absorbed
| Better GI absorb
31
Ampicillin (extended-spectrum)
* delayed hypersensitivity rxn + non - immune skin rxn
| * only use amoxi, this one is IV in hospital
32
Piperacillin (IV/IM)
| extended-spectrum
* Inactivated by gastric acid
* only IV/IM
* PSEUDOMONAS ("P")
33
Amoxi/clavulanic acid
| +B lac inhbitor
*clav = suicide inhibitor of B-lactamase (no intrinsic antibacterial activity)
34
Cephalosporins - 1st gen
GRAM +
some gram -
* Cefalozin (IV) - surgery prophylaxis (skin gram +)
* Cephalexin (PO)
INACTIVATED BY:
* broad spectrum B-lacmase
* Ext. spectr. B-Lacmase
* don't bind PBP2a
35
Cephalosporins - 2nd gen
LESS IMPORTANT
More gram - than +
Cefoxitin - resistant to b-lactmase
Cefuroxime
INACTIVATED BY:
* broad spectrum B-lacmase
* Ext. spectr. B-Lacmase
* don't bind PBP2a
36
Cephalosporins - 4th gen + 5
LESS IMPORTANT
More gram - than +
4th - Cefepime
5th - MRSA
INACTIVATED BY:
*don't bind PBP2a
37
Cephalosporins 3rd gen
More gram (-) than (+)
* Ceftriaxone - meningitis, lyme gonorrhea
* Ceftazidime - Pseudomonas (turn on dime)
INACTIVATED BY:
* Ext. spectr. B-Lacmase
* don't bind PBP2a
38
which Cephalosporin generation penetrates CNS (meningitis)?
Ceph gen 3
| 1 + 2 don't penetrate
39
How are cephalosporins excreted?
kidney
40
Cephalosporins
S.E.
* cross-allergenicity w/ penicillin
| * NEPHROTOXIC (adds to aminoglycosides too)
41
Carbapenem characteristics
Imipenem/cilastin
Meropenem
* Gram +/- rods, pseudomonas
* last resort Rx
* kill ESB-lactamases
42
Carbapenem Rx characteristics
*Imipenem/cilastine - cilastin blocks dehydropeptidase I (imipenim renal hydrolysis)
(lasts longer!!) (watch for renal problems!)
*Meropenem - no cilastin needed
43
Monobactams
*Aztreonam = Gram -
Enterobacteriaceae , Pseudomonas
*S.E. - no cross-allergenicity w/ penicillins/ceph
44
All "mycins" come from what bacteria?
Streptomyces
45
Mycins
Streptomycin (aminoglycoside)
Vancomycin (glycopeptide)
Clarithromycin (macrolide)
Clindamycin (lincosamide)
46
Vancomycin
(glycopeptide)
Characteristics
* IV, kidney excrete
* Gram +, pseudo, C. difficile
* block glucotrasferase (peptidoglycan synth)
* can't add dissacharide to polymer
* bind terminal D-ala-D-ala
47
Vancomycine
(glycopeptide)
S.E. + resistance
S.E. - "N.O.T. that toxic!"
*Red man (flushing)
Resistance- D-lactate
* VRE to MRSA
* Use - Linezolid, Daptomycin
48
Linezolid
| Oxazolidinone
* Gram +
* when pen, ceph, vanc don't work (last resort)
* MRSA/VRE + can't use Vanc
* liver metabolism
49
Linezolid
(Oxazolidinone)
Resistance + S.E.
* No cross resistance- bind 23S RNA (50S subunit), blocks 70S initiation complex formation
* Resistance - 23S RNA mutation
* S.E. - neuropathy (periph/optic)
- myelosuppression
- HTN w/ tyramine (MAO inhibitor)
50
Daptomycin
| Cyclic Lipopeptide
* after pen, ceph, vanc, linezolid (vanc resistance)
* Gram + (ALL)
* forms K efflux pore (little resistance)
* urine excretion
51
Daptomycin
(Cyclic Lipopeptide)
S.E.
* muscle weakness/discomfort
| * not w/ statins (rhabdomyolysis)
52
Which wall agent alternative inhibits protein synthesis?
macrolides:
* Clarythromycin (PO,IV)
* Azithromycin (PO,IV)
* Erythromycin (IV, PO)
bind to 50S, stop translocation
53
Which wall agent alternatives are indicated for anaerobes?
*Clindamycin (PO,IV) (lincosamide)
(oral>bowel) Gram +/-
*Metronidazole (PO,IV) (nitromidazole)
(bowel sterilizer)
54
Which wall agent alternative is a DNA breaker?
Metronidazole (PO,IV)
| nitroimidazole
55
Macrolides
Use
Gram + more
for allergy to pen/ceph
for Gram + B-lactam resistant
56
MLS cross drug resistance?
Macrolides, lincosamides, streptogamins
57
Why is erythromycin bad?
| macrolide
* food interferes with absorption
* biliary excretion
* drug interactions due to inhibition of P450
* GI intolerance (motilin receptors)
* Hepatotoxic - acute cholestatic hepatitis
* reversible hearing loss
* QT prolongation (Vtac)
58
What is effect of inhibiting P-gp/CYP 3A4 ?
higher bioavailability
59
Clarythromycin
(macrolide)
S.E.
* reversible hearing loss
* teratogenic
* drug drug interaction
* CYP3A4 inhibition
60
Azythromycin
| macrolide
* penetrates tissues well
* keeps working after you stop (t 1/2 = 3days)
* NO P-450 inhibition
61
Clindamycin
Use
* Gram + aerobe
* Gram +/- anaerobe
* MRSA
62
Clindamycin
resistance + S.E.
*if resistant, then macrolide resistant (not vice versa)
*liver metab, out in urine + bile
(Hepatic disease?)
*causes Pseudomembranous colitis (c.difficile)
63
Metronidazole (PO,IV)
| nitroimidazole
* anaerobic infxn, C.difficile (colitis)
* bowel surgery
* Disrupt DNA (covalent bonds)
64
Metronidazole (PO,IV)
(nitroimidazole)
resistance + S.E.
Resistance- less nitroreductase
* S.E. - w/alcohol = disulfiram-like rxn (N/V)
* P-450 inhibition
* metallic taste
* dark red brown urine
