penicillin antibiotics

Question 1

5 questions in empiric coverage

Answer 1

What is the patient at risk for?
gram +
Gram-_
anaerobe
atypical
MDRO

Question 2

bacterial resistance

Answer 2

action of antimicrobial agents
range of targets within bacterial cell
inhibition of bacterial growth or killing the bacterical cell

resistance
reduction oin or loss of the antibacterial effect

resistance mechanisms:
properties or alteration in the bacterium
result in reduced antimicrobial activity

bacteria can be resistant to single or multiple antimicrobials

bacteria mechanisms of resistance

alteration or bypassing of drug target

1. altered access to drugs target
   modifications of drug activity
2. resistant bacteria have a combination of mechanisms
3. mutations in bacterial chromosomal genes
   acquisition of new genes by DNA transfer
   acquired oneself replicating plasmids

minimum inhibitory concentration (MIC)
assessing the occurrence and magnitude of resistance

Question 3

bacterial resistance

Answer 3

transformation
upptake of fragments of enviromental DNA from related bacterial species

Beta-lactates :

antibiotic Degradation
Breakdown of the core of beta-lactam ring
destroys drug activity

beta lactamase inhibitor
  sublactam or tazobactam
     little to no antibacterial activity
      inhibits plasmid medicated beta lactamases

extended spectrum beta lactamase ( ESBL)
ability to inactivate all pencillin’
early generation cephalosproins

Question 4

Mimimun Inhibitroy concentration (MIC)

Answer 4

incubated organisms given with increasing concentrations

the lowest concentration of antibiotic with no visible growth

MIC or breakpoint

organisms
site of infection
FDA regulation

antibiotics managemetn
based on lowest MIC value

Question 5

penicillin allergy (beta-lactam )

Answer 5

10% report allergy
90% may be tolerate
cross-reactivity with cephalosporins
2% (newest data)
,1% cross-reactivity with carbapenems

Cephalsoproin allergy
37% in class cross reactivity
true allergy does not correlate to PCN allergy

Question 6

Penicillinase resistant penicillin ( nafcillin )

Answer 6

Mechanism of action:
inhibits cell wall mucopeptide
bactericidal

clinical application
gram-positive
MSSA
CoNS
CoPS

avoid use
enterococci or MRSA
side effect /adv reaction
acute interstitial nephritis , pheblitis , bone marow suppression

Question 7

aminopenicillin ( ampicillin)

Answer 7

mechanism of action:
bacteriacydial
inhibits cell wall mucopeptide synthesis

clinical application
some gram-coverage
streptococcus and enterococcus faeclis
CNS coverage
achromyces spp
Borelliea bugdefri
Clostridia
listeria monocyte-genes
Neisseria meningitis
pustruella mulcudia
peptiomplus

avoid use
staphlyococcus
side effect adverse reaction:
rash (65-100% ) with acute mononeucliosis

not a true allergy

Question 8

aminopenicillin ( ampicillin/sulbactam)
unasyn

Answer 8

mechanism of action:
bactericidal
inhibits cell wall mucopeptide synthesis
inhibits beta lactamases

clinical application
gram + gram - & anerobes
increasing resistance among arobic gram-rods
Haemophilus influenzae or pasturella multicada
common usage

avoid use
streptococcus
side effects/adverse reactions
eosinophelia , phlebitis , fever , rash

Question 9

antipseudomonal penicilllin
(piperacillin/tazobactam) zosyn

Answer 9

mechanism of action
bacterialcidal
pripecillin inhibits cell wall mucopeptide syntheis
tazabactam inhibitsbeta-lactmaces

clinical application:
gram + MSSA streptococcus
gram - GNR
anaerobes
MDRO ( pseudomonas)

avoid use
ESBL

side effects adverse reaction
aki with vancomycin
impaired platelet aggeration
bone marrow suppression