Penicillins

Question 1

Beta lactam antibiotics

Answer 1

Penicillins
Cephalosporins
Carbapenems
Monobactams

Question 2

Narrow Spectrum PCNS

Answer 2

PCN V (PO)
PCN G

Question 3

Penicillinase Resistant PCNs are also called

Answer 3

Antistaphylococcal PCNs

Question 4

Penicillinase Resistant PCNs

Answer 4

Nafcillin (IV)
Dicloxacillin (PO)
Oxacillin (IM, IV)

Question 5

Extended spectrum PCNs

Answer 5

Amoxicillin
Ampicillin
Ticarcillin
Piperacillin

Question 6

Subgroups in Extended Spectrum PCNs

Answer 6

Aminopenicillins
Antipseudomonal pcns

Question 7

PCN MOA

Answer 7

inhibit bacterial cell wall synthesis –> penicillin binds to penicillin binding proteins

Question 8

Why are PCNs highly selective?

Answer 8

mammalian cells don’t have a cell wall

Question 9

What types of bacteria do PCNs attack? Bactericidal or static?

Answer 9

Gram positive

Bactericidal

Question 10

Basic structure of PCNs

Answer 10

beta lactam ring (BLR)
thiazolidine ring (TR)

Question 11

How do PCNs differ from one another?

Answer 11

substitution of R group

Question 12

Which PCNs have a large bulky R group?

Answer 12

Penicillinase-Resistant Drugs

Question 13

DOC natural PCN

Answer 13

syphilis
Group A strep pharyngitis

Question 14

What bacteria is almost completely resistant to natural PCNs due to penicillinases?

Answer 14

staphylococci

Question 15

Are natural PCNs a good choice for empiric therapy?

Answer 15

no

Question 16

Staphylococci that are resistant to penicillinase resistant PCNs

Answer 16

methicillin resistant staphylococcus aureus (MRSA)

Question 17

Should fluoroquinolones be used to empiric MRSA therapy?

Answer 17

no

Question 18

DOC penicillinase resistant PCNs

Answer 18

SSTI and endocarditis caused by MSSA

Question 19

Advantages of Penicillinase Resistant PCNs over Vancomycin

Answer 19

more rapidly bactericidal
oral administration

Question 20

Augmentin

Answer 20

amoxicillin + clavulanate

Question 21

Unaysn

Answer 21

ampicillin + sulbactam

Question 22

Zosyn (IV)

Answer 22

piperacillin/tazobactam

Question 23

Timentin (IV)

Answer 23

ticarcillin/clavulanate

Question 24

What is ampicillin + gentamicin used for?

Answer 24

Neonatal infections (meningitis)

Question 25

what has become increasingly resistant to amoxicillin?

Answer 25

Streptococcus pneumoniae (pneumococci)

Question 26

Resistance to PCNs can be caused by

Answer 26

beta lactamase
decreased affinity of PBP for drug
decreased entry of drug via porin

Question 27

Amoxicillin oral DOC

Answer 27

otitis media

Question 28

Ampicillin IV DOC

Answer 28

susceptible enterococci and Listeria monocytogenes

Question 29

Which aminopenicillin has better bioavailability?

Answer 29

Amoxicillin

Question 30

Are aminopenicillins bacteriocidal or static?

Answer 30

Generally bactericidal

but they are bacteriostatic against enterococci

Question 31

What do you add for synergy to aminopencillins against enterococci?

Answer 31

aminoglycoside — then it will be bactericidal

Question 32

Why are antipseudomonal PCNs given IV?

Answer 32

they are destroyed by gastric acid

Question 33

Which combination agent is the only one given PO?

Answer 33

Augmentin

Question 34

What penicillins are destroyed by gastric acid?

Answer 34

naturally occurring PCNs
Antipseudomonal PCNs

Question 35

How are most PCNs eliminated?

Answer 35

renal tubular secretion

Question 36

Half lives of most PCNs?

Answer 36

30-60 min

Question 37

Which PCNs are eliminated by biliary excretion?

Answer 37

Ampicillin and nafcillin

Question 38

ADE of PCNs

Answer 38

Hypersensitivity –> urticaria, angioedema, anaphylactic shock and interstitial nephritis, hepatitis, serum sickness
Diarrhea
Neurotoxicity (can cause seizures)

Question 39

Which PCN is most likely to cause maculopapular rash in pts with viral infection?

Answer 39

Ampicillin