Exam 2 - Erdman (Lecture 1 - beta lactams)

Question 1

aerobic vs. anaerobic bacteria

Question 2

gram (-) vs. (+)

Question 3

vancomycin only hits gram (-) or gram (+)?

Answer 3

gram (+)

Question 4

metronidazole only has activity on which bacteria

Answer 4

anaerobic bacteria

Question 5

aztreoman only has activity against which bacteria

Answer 5

gram (-)

Question 6

make cards on which drugs have activity against the target organisms (shaded rows - these commonly cause infections in humans or have some kind of resistance mechanism that we should consider when choosing an antibiotic)

Question 7

most commonly used antibiotic in hospital

Answer 7

B-lactams (65%)

Question 8

6 general characteristics of B-lactam antibiotics
-number 1

Answer 8

Same MOA: inhibit cell wall synthesis

Question 9

6 general characteristics of B-lactam antibiotics
-number 2

Answer 9

Same MOR: Beta-lactamase degredation, PBP alteration, decreased penetration

Question 10

6 general characteristics of B-lactam antibiotics
-number 3

Answer 10

Bactericidal in a TIME-DEPENDENT manner, except against Enterococcus spp.

Question 11

6 general characteristics of B-lactam antibiotics
-number 4

Answer 11

Short elimination half life of <2 hours

Question 12

6 general characteristics of B-lactam antibiotics
-number 5

Answer 12

Primarily eliminated unchanged by the kidneys (except nafcillin, oxacillin, ceftriaxone, cefoperazone)

Question 13

6 general characteristics of B-lactam antibiotics
-number 6

Answer 13

cross-allergenicity: except aztreonam

Question 14

T/F: all penicillins are bactericidal against all bacteria

Answer 14

False, all bacteria except Enterococcus

Question 15

Pencillins MOR - 1

Answer 15

production of Beta-lactamase enzymes
-most important an most common type, hydrolyzes B-lactam ring

Question 16

Gram (+) B-lactam resistant strains of bacteria

Answer 16

penicillin-resistant Staph. aureus

Question 17

Gram (-) B-lactam resistant strains of bacteria

Answer 17

Haemophilus influenzae, Moraxella catarrhalis, neisseria gonorrhoeae, E. coli, Klebsiella pneumoniae, Enterobacter spp.
-concentrated where PBPs are, why its more common in gram (-)

Question 18

Gram (-) anaerobes B-lactam resistant strains of bacteria

Answer 18

bacteroides fragilis

Question 19

Pencillins MOR - 2

Answer 19

Alteration in structure of PBPs leading to decreased binding affinity –> MRSA and PRSP
-B-lactamase inhibitors do not work against these bc of MOA

Question 20

MRSA stands for

Answer 20

methicillin resistant Staphylococcus aureus

Question 21

PRSP stands for

Answer 21

Penicillin resistant Streptococcus Pneumoniae

Question 22

Pencillins MOR - 3

Answer 22

alteration of outer membrane porin proteins leading to decreased penetration

Question 23

Four penicillins still used in practice

Answer 23

Aqueous pen G (IV)
Benzathine pen G (IM)
Procaine pen G (IM)
Phenoxymethyl penicillin (penicillin VK)

Question 24

_______ is the most common penicillinase resistant penicillin we use clinically

Answer 24

Nafcillin
-basically the most resistant to penicillinases (B-lactamses)

Question 25

3 penicillinase-resistant penicillins

Answer 25

Nafcillin Methicillin (no longer used) Dicloxacillin (oral)

Question 26

methicillin susceptible also means?

Answer 26

Nafcillin susceptible cloxacillin susceptible dicloxacillin susceptible oxacillin susceptible

Question 27

why were aminopenicillins developed

Answer 27

to have some agents with enhanced activity against gram (-) aerobes

Question 28

drug of choice for enterococcus infections

Answer 28

ampicillin

Question 29

What aminopenicillins are used for today

Answer 29

SHEP Salmonella, Shigella H. influenzae some E. coli Proteus mirabilis

Question 30

only carboxypenicillin we need to know

Answer 30

ticarcillin

Question 31

what changes occur when going from aminopenicillins to carboxypenicillins

Answer 31

-lose gram (+) activity -expanded activity against gram (-) -SHEP (+MEPP) Morganella Enterobacter Pseudomonas (target organism, tough to kill but ticarcillin can) Providencia

Question 32

Ureidopenicillin we need to know

Answer 32

pipericillin

Question 33

why Ureidopenicillins were developed

Answer 33

need for agents with even more enhanced activity against gram (-) bacteria -hits pseudomonas

Question 34

Which is the penicillin (not drug) of choice for pseudomonas?

Answer 34

piperacillin, it is the most active

Question 35

what changes occur when going from carboxypenicillins to ureidopenicillins

Answer 35

SHEPMEPP (+KS) some Klebsiella spp. Serratia marcescens

Question 36

B-lactamase inhibitors do not work against _____&_____. Why?

Answer 36

PRSP, MRSA -resistance is due to PBP, not B-lactamases

Question 37

B-lactamase inhibitor combos and what organisms they cover -Unasyn, Augmentin, Timentin, Zosyn

Answer 37

Gram positives -MSSA Anaerobes -Bacteroides spp. Gram negatives -H. influenzae -E. coli -Proteus spp. -Klebsiella spp. -Neisseria gonorrhoeae -Moraxella catarrhalis

Question 38

penicillins are time dependent or concentration dependent?

Answer 38

time dependent

Question 39

goal of dosing for penicillins

Answer 39

maintain serum conc. > MIC of infecting bacteria for 50% of dosing interval

Question 40

oral penicillins for (mild-moderate infections or moderate-severe)?

Answer 40

mild-moderate

Question 41

IV penicillins for (mild-moderate infections or moderate-severe)?

Answer 41

moderate-severe

Question 42

Penicillins are hydrophillic and are therefore _______ distributed

Answer 42

widely

Question 43

which penicillins penetrate the CSF?

Answer 43

all parenteral ones

Question 44

adequate concentrations of penicillins are achieved in CSF when what two things are present?

Answer 44

If there are inflamed meninges and we use maximal IV doses

Question 45

penicillins are eliminated unchanged by _____

Answer 45

kidneys

Question 46

Penicillin sodium load (how much sodium comes with each administration) sodium Pen G: Nafcillin: Ticarcillin: pipericillin:

Answer 46

: 2.0 mEq per 1 million units : 2.9 mEq per gram : 5.2 mEq per gram : 1.85 mEq per gram

Question 47

Penicillins must be used with caution in ____ and _____ pts

Answer 47

CHF, renal insufficiency

Question 48

Penicillins are for sure the drug of choice in which infection type?

Answer 48

syphilis

Question 49

Augmentin? more like Dogmentin because its used in?

Answer 49

animal or human bite infections

Question 50

cross-reactivity exists among ____ penicillins and even some other _________

Answer 50

ALL, B-lactams

Question 51

AE of penicillins

Answer 51

hypersensitivity neurologic hematologic interstitial nephritis

Question 52

clavulanate specifically causes what side effect? (dose dependent)

Answer 52

diarrhea