抗生素使用指南 （英文）Simple Antibiotic Guide
How do β-lactams kill ?
How do β-lactams kill ?
• Inhibit the production of bacterial cell wall • Therefore they don’t kill our cells, but they
Flagyl
BACTERIOCIDAL or STATIC ???
Beta lactams
CIDAL
Aminoglycosides
CIDAL
Quinolones
CIDAL
Tetracyclines
BACTERIOSTATIC
Azithromycin, Clindamycin BOTH it depends
Example of synergy: cell wall active drug + protein inhibitor
How do β-lactams kill the enterococcus?
How do β-lactams kill the enterococcus?
Trick question- it doesn’t . Only inhibits their growth………………
Which brings us to the issue of Cidal vs Static antibiotics (and synergy also)
WHAT is Inhibitory (static)?
• In a test tube there is no change over time
So is it ever important to use a cidal antibiotic?
• Yes - for Endocarditis always always always (is that clear???)
• No - for almost everything else • Maybe (for those of you that can’t decide)-
*** Remember there is going to be a twist to this answer later on
CIDAL or STATIC ???
Beta lactams CIDAL Aminoglycosides CIDAL too Quinolones
CIDAL or STATIC ???
don’t kill mycoplasma or chlamydia either (they lack a cell wall….remember ?)
What about other antibiotics?
• Aminoglycosides - Macrolides – Tetracyclines- Clindamycin
4.5 B 3 B
2BΒιβλιοθήκη 1-0.5 B300 M
History of Bacteria and
for neutropenic patients in treatment of meningitis for osteomyelitis
CIDAL or STATIC ???
Beta lactams
CIDAL or STATIC ???
Beta lactams Aminoglycosides
CIDAL ****
Flagyl
CIDAL
Pharmakokinetics & Pharmakodynamics (Is more better?)
• peak level (ie concentration) = rate of kill (aminoglycosides, quinolones)
• Time > MIC (duration) = rate of kill (beta lactams, clindamycin, macrolides)
Beta lactams Aminoglycosides Quinolones Tetracyclines
CIDAL CIDAL CIDAL
BACTERIOCIDAL or STATIC ???
Beta lactams Aminoglycosides Quinolones Tetracyclines Azithromycin
CIDAL CIDAL CIDAL STATIC
BACTERIOCIDAL or STATIC ???
Beta lactams
CIDAL
Aminoglycosides
CIDAL
Quinolones
CIDAL
Tetracyclines
STATIC
Azithromycin, Clindamycin BOTH
= MIC
What is CIDAL ?
DEAD ? ALMOST DEAD ? MOSTLY DEAD? EVENTUALY DEAD ?
What is CIDAL ?
In 24 hours 99.9% of the buggers are DEAD
So is it ever important to use a cidal antibiotic?
MIC
Dose interval
History of Bacteria and
BIG BANG
Antibiotics
4.5 B 3 B
2B
1-0.5 B
300 M
History of Bacteria and
BIG BANG
Antibiotics
Anaerobic bacteria appear O2 & the emergence of Aerobes
All inhibit protein synthesis via ribosomes
• Quinolones block DNA synthesis
• Daptomycin blocks AA transport
What is Synergy and when do you want it?
Additive is: 2 + 2 = 4 Synergy is: 2 + 2 = 7