beta lactams

Question 1

what are the different beta lactam ?

Answer 1

penicillins
carbapanems
aztreonam
cephalosporins

Question 2

what are the carbapanems ?

Answer 2

imipenem
meropenem
ertapenem

Question 3

what makes carbapenms different to the penicillins ?

Answer 3

carbapanems are resistant to cleavage by beta lactamase

Question 4

what are the only antibiotics that can resist ESBL ?

Answer 4

carbapenems

Question 5

where are ESBLs found ?

Answer 5

gram negative bacteria only produce ESBL
pseudomonas
klebsiella

Question 6

what is the problem with impenem ?

Answer 6

metabolized in the kidneys and produced nephrotoxic metabolites

Question 7

what enzyme breaks down imipenem and how is this problem solved ?

Answer 7

the enzyme is dehydropeptidase I
problem solved by giving cilastatin
specific to imipenem

Question 8

what are the common side effects of carbapenem ?

Answer 8

GI uoset
skin rash
seizures by inhibition of GABA receptors

Question 9

which of the carbapenems carries a lower risk of seizures ?

Answer 9

meropenem

Question 10

what is the mode of action of azteronam ?

Answer 10

binds to penicillin binding proteins specifically PBP 3 and is resistant to beta lactamases

Question 11

what are the clinical uses of aztreonam ?

Answer 11

used only for gram negative rods
used for patients with peniciilin sensitivity and those with renal insufficiency

Question 12

what drug is synergistic with aztreonam ?

Answer 12

aminoglycosides

Question 13

what are the 1st generation cephalosporins ?

Answer 13

cefazolin
cephalexin

Question 14

what are the main clinical uses of first generation antibiotics ?

Answer 14

surgical wound skin infection
pre op prevention

Question 15

what bacteria are covered by 1srt generation cephalosporins ?

Answer 15

PEcK
proteus
E coli
lebsiella

Question 16

what are the 2nd generation cephalosporin ?

Answer 16

cefuroxime
cefoxitine
cefotetan

Question 17

what are the bacteria that 2nd generation cephalosporins cover ?

Answer 17

HENS PEcK
H influenza
Enterobacter
Neisseria
Serratia
Proteus
E coi
Klebsiella

Question 18

if a child were to present with E coli UTI what is the most appropriate drug to use ?

Answer 18

cefuroxime
no fluoroquinolones used

Question 19

what drug is used for children presenting with appendicitis pre op ?

Answer 19

Cefoxitin / cefotetan

Question 20

what are the 3rd generation cephalosporins ?

Answer 20

ceftriaxone ceftazidine
cefpodoxime

Question 21

what is the third generation cephalosporins can be used for pseudomonal infections ?

Answer 21

ceftazidine

Question 22

what diseases is ceftraxione commonly used for ?

Answer 22

meningitis
disseminated lyme disease
gonorrhea
ceftriaxone can cross the blood brain barrier

Question 23

what is the 4th generation cephalosporin ?

Answer 23

cefepime

Question 24

what is the 5th generation cephalosporin ?

Answer 24

ceftaroline

Question 25

what does the b lactmase sensitivity depend on ?

Answer 25

based on the side chain the simpler the side chain the more likely that the b lactmase will break down the antimicrobial

Question 26

what is the drug of choice when it comes to ESBL bacteria ?

Answer 26

carbapenems

Question 27

which of the cepahlosporins is active against MRSA and what is its mechanism of action ?

Answer 27

ceftaroline binds to PBP2a which is a MRSA specific PBP also covers VRSA

Question 28

what are the adverse reactions associated with cephalosporins ?

Answer 28

hypersensitivity reaction vitamin k deficiency disulfram reaction

Question 29

what are the causes of bleeding in association with cephalosporin administration ?

Answer 29

1- vitamin K deficiency ( could happen with any antibiotic) commony a problem for patients on warfarin 2- hypoprothrombinemia

Question 30

what are our sources of vitamin K ?

Answer 30

vitamin K1 comes from our diet vitamin K 2 comes from GI bacteria

Question 31

what type of patient is more likely to develop hypothrombonemia as a result of cephalosporin administration ?

Answer 31

malnourished patients

Question 32

how can cephalosporins cause nephrotoxicity ?

Answer 32

when given with aminoglycosides

Question 33

what is a disulfram reaction ?

Answer 33

happens with the consumption of alcohol with cephalosporins happens due to the inhibition of aldehyde dehydrogenase enzyme

Question 34

what are the organisms that are not covered by 1st to 4th cephalosporins ?

Answer 34

LAME Listeria Attypicals ( chlamydia, mycoplasma) MRSA Enterococci