Pharm - Cell Wall Inhibitors

Question 1

beta-lactam

Answer 1

four membered ring
ketone next to amino group
hydrogen is next to the keto-group (below plane)

Question 2

why are carbapenems more resistant to beta-lactamases?

Answer 2

H comes above the plane and stabilizes the molecule

Question 3

structure of penicillins

Answer 3

contain Ring A (thiazolidine) attached to rink B (beta-lactam)
beta-lactam has an R group attached

Question 4

MOA of penicillin

Answer 4

Beta-lactams bind PBP’s covalently. PBPs catalyze transpeptidase run that allows cross linking to form bacterial cell walls –> no cell wall synthesis causes bacterial death

Question 5

Penicillin G - what organisms are sensitive?

Answer 5

streptococci, enterococcus, oral anaerobes, meningococcus, syphilis

Question 6

Penicillin G - what organisms are resistant?

Answer 6

most staph (>85%), some pneumococcus (10-30%), bowel anaerobe, most GNRs

Question 7

Penicillin V

Answer 7

like penicillin G, but given orally (more resistant to stomach acid)

Question 8

procaine Pen G

Answer 8

given IM, w/ peak @ 1-4 hrs, duration 1-2 days

Question 9

benzathine Pen G

Answer 9

given IM, lasts longer than procaine

given IM w/ peak 13-24 hrs, duration 1-4 wks

Question 10

Ampiclllin - what organisms are sensitive?

Answer 10

strep, enterococcus, oral anaerobes, Listeria, some GNRs

Question 11

amoxicillin

Answer 11

newer version of ampicillin, only given PO, wider spectrum of action

Question 12

anti-staph penicillins

Answer 12

methicillin = 1st, but nephrotoxic
nafcillins or oxacillin used now IV for serious infection
oral version dicloxacillin

Question 13

nafcillin vs. dicloxacillin

Answer 13

anti-staph (for MSSA)

nafcillin is IV, dicloxacillin is PO

Question 14

piperacillin

Answer 14

coverage includes pseudomonas, klebsiella, many other GNRs (ICU pneumonia, intra-abdominal infxn, urosepsis)
but, doesn’t work against enterococcus + resistance develops quickly w/ mono therapy (combine w/ tobramycin)

Question 15

what drug is normally used for intra-abdominal infections?

Answer 15

pipercillin - covers mixed GNRs, anaerobes, enterococcus

Question 16

abx choice for nosocomial pneumonia?

Answer 16

pipercillin - these are often caused by GNR

Question 17

abx for pseudomonas

Answer 17

pipercillin

Question 18

which organisms are beta-lactamase inhibitors more effective against? not effective agaist?

Answer 18

staph, H. flu, N. gornorrhea, salmonella, shigella, E coli, K pneumoniae
NOT good against gram neg rods - enterobacter, citrobacter, serratia, pseudomonas

Question 19

augmentin

Answer 19

PO amoxicillin + clavulonic acid

Question 20

unasyn

Answer 20

IV ampicillin + sulbactam

Question 21

zosyn

Answer 21

IV pipercillin + tazobactam

Question 22

cephalosporins

Answer 22

similar to penicillin in structure, MOA, toxicities
but MORE STABLE to beta-lactamases –> broader spectrum
NOT active against enterococci, Listeria

Question 23

differences b/t generations of cephalosporin

Answer 23

1st gen better against GP (staph, strep)

later drugs better against GN aerobic (e. coli)

Question 24

cephazolin/cephalexin

Answer 24

1st gen cephalosporin,

Question 25

ceftriaxone vs. ceftazidime

Answer 25

both 3rd gen cephalosporin, but ceftazidime is better for GNRs including pseudomonas

Question 26

ceftaroline

Answer 26

5th gen cephalosporin -NEW
wider spectrum, used for GNRs and GPCs
CABP, skin infections

Question 27

adverse effects of cephalosporins

Answer 27

don’t give to pts who have had IgE mediated penicillin allergies