ABX review

Question 1

Bactericidal agents important when patient is already immunocompromised

Answer 1

beta lactams
bacitracin
Fosomycin
Vanco
Isoniazid
Aminoglycosides
Quinpristin
Metronidazole
Polymixins (colistin)
Fluroqionolones (-floxacins)
Tigecylcine
Rifampin
Pyrazinamide

Question 2

Microbial resistance of beta lactams via

Answer 2

altered targets, decreased permeability, enzymatic inactivation

Question 3

main classes of GI superinfections

Answer 3

Intestinal Candidiasis (tx oral nystatin)
Staph Enterocolitis (life threatening, oral vancomycin)
Pseudomembranous colitis (C. diff usually from clinda; tx metronidazole, vanco if resistant)

Question 4

Inhibitors of cell wall synthesis intracellular agents

Answer 4

Fosomycin
Cycloserine
Bacitracin stops the transport of building blocks out of the cell as well

Question 5

Inhibitors of cell wall synthesis extracellular transglycosylation and transpeptidation

Answer 5

transglycosylation: Vancomycin
Transpeptidation: makes cell wall rigid–> Beta-lactams

Question 6

GM+ beta lactams, antistaph, and extended spectrum

Answer 6

GM+: Pen V and Pen B
Anti staph: nafcillin, methicillin, isoxazolyl penicillins
Extended spectrum: Ampicillin, Amoxacillin, piperacillin, Ticarcillin

Question 7

What are the anti pseudomonal penicillins

Answer 7

Piperacillin, ticarcillin (rapid resistance so use in combo with aminoglycoside)

Question 8

cephalosporins are inhibitors of cell wall synthesis via intracellular mechanisms 1st through 5th gen speificity

Answer 8

1st gen cephalosporin (cefazolin parenteral, cephalexin oral)–> GM+

2nd gen cephalosporin (cefaclor oral)–> GM+ and increased against GM-

3rd gen (Ceftriaxone, cefotaxime, cefexime oral)–>GM-

4th gen (cefepime)–> GM+ and GM- activity

Question 9

1st gen cephalosporin (cefazolin parenteral, cephalexin oral) used for

Answer 9

Staph and strep cellulitis, surgical prophylaxis except abdominal which you use a 2nd gen sporin for

Question 10

2nd gen cephalosporin (cefaclor oral) uses

Answer 10

E. coli, kliebsiella, proteus, H. flu, Moraxella catarrhalis

PID, Diverticulitis, Surgical prophylaxis (for abdominal surgery), pneumonia, bronchitis (H. flu)

Question 11

3rd gen (Ceftriaxone, cefotaxime, cefexime oral) uses

Answer 11

Ceftazidine--> pseudomonas
Ceftazidime-->osteomyelitis
Ceftriaxone-->Meningitidis N. gonorrhea
Ceftriaxone (parenteral) or Cefexime(oral)--> Gonorhea
CAP
Lyme disease

Cross the BBB, helpful for meninigitis

Question 12

4th gen (cefepime) uses

Answer 12

GM+ and GM—> neutropenic fever

Question 13

5th gen cephalosporin uses

Answer 13

MRSA, CAP, skin infections

Question 14

Beta lactam that you can use with penicillin allergy with aminoglycoside to treat pseudomonas

Answer 14

Aztreonam

Question 15

Beta lactam that is inactivated by renal dipeptidase so administer with cilastatin

Answer 15

Carbapenems; pseudomonas develops resistance rapidly, administer with aminoglycoside

IV only

Question 16

penems that aren’t inactivated by renal dipeptidase

Answer 16

Meropenem, doripenem, ertapenem

Question 17

Abx that inhibits transglycosylation of cell wall synthesis, works against GM+ cillin resistant and is orally administers for tx of C. diff

Answer 17

Vancomycin

Question 18

Abx that causes Red man syndrome, ototoxicity, renal toxicity which has synergistic toxicity with aminoglycosides

Answer 18

Vancomycin

Question 19

Vancomycin used for

Answer 19

S. aureus
Hospital acquired MRSA
Enterococci species
GM+ in penicillin allergies
C. diff though metronidazole DOC

Question 20

Abx that inhibits cytoplasmic step in cell wall precursory synthesis

Answer 20

Fosfomycin, transported into cell via G6P transporter

single dose tx of UTIs

Question 21

Bacitracin acts intracellularly to inhibit cell wall synthesis, is only GM+ and topical, and has was sort of toxicity that makes it used only topically

Answer 21

Nephrotoxicity

Question 22

MOA of quinolones

Answer 22

DNA gyrase inhibitor, block the unwinding of DNA

Question 23

Why are quinolones fluorinated?

Answer 23

to slow down the clearance, probenacid can also help with this.

Question 24

1st, 2nd, 3rd, 4th gen fluoroquinolones

nor cipping levt (over) Moxi

Answer 24

1st gen: norfloxacin (UTIs)

2nd gen: Ciprofloxacin BID (Gonococcus and Pseudomonas, Chlamydi, Myco pneumo)

3rd gen: Levofloxacin (S. pneumo, enterococci, MRSA, Drug resistant Respiratory tract infections)

4th gen: Moxifloxacin/gemifloxacin “Respiratory Abx”

Question 25

Main tx for TB and leprosy that inhibits DNA dependent RNA polymerase

Answer 25

chronic tx with isoniazid and Rifampin

Question 26

What is preferred in the tx of TB or leprosys in pts with HIV who are on HAART

Answer 26

Rifabutin

Question 27

Nitrofurantoin used for ______ because it is excreted rapidly and even when IV it doesn’t have systemic distribution

Answer 27

UTIs
need acidified urin

some G6PDase hem anemia

Question 28

What Abx makes the cell wall more permeable?

Answer 28

polymixins for GM-, mainly topical

mainly topical because of systemic toxicity (NEPHROTOXIC)

Colistin is used as last resort for Pseudomonas

Question 29

Abx that binds to the cell membrane and causes cell depolarization, used only for GM+, IV, Severe skin infections or VRE

Answer 29

Daptomycin

Question 30

Abx that binds to isoleucyl transfer-RNA synthetase, used topically for impetigo (staph aureues or streptococcus pyogenes)

Answer 30

Mupirocin

Question 31

Prophylaxis for Pneumocysitis jirovecii

Answer 31

TMP-Sulfamethoxazole

Question 32

Prophylaxis for malaria

Answer 32

Chloroquine

Question 33

Prophylaxis for TB

Answer 33

Isoniazid

Question 34

prophylaxis for Mycobacterium avium in AIDs patients

Answer 34

Azithromycin