Penicillin Flashcards
Penicillins are what kind of active agent?
Cell wall active
Inhibits protein synthesis in tuberculosis by inhibiting RNA Polymerase.
Rifampin
The active component of Penicillin.
Beta-lactam ring
Penicillin MOA
Binds to Transpeptidase, preventing the formation of the bacterial cell wall.
Function of Transpeptidase.
1) Links peptidoglycans together to form the bacterial cell wall..
2) Allows glycoside residues to stick to the the peptidoglycan chain.
This enzyme is bifunctional in the synthesis of the bacterial peptidoglycan cell wall.
Transpeptidase
Transpeptidase activity is called this bc of it’s bifunctional nature.
Transglycolase activity
Penicillins only work on these organisms.
Actively replicating
Penicillins will not kill these organisms.
Static or stationary phase bacteria.
These are most commonly encoded on plasmids to cause Penicillin resistance.
Beta Lactamases
Abbreviation for Transpeptidase.
PBP
Alterations in these can decrease susceptibility to many penicillins.
PBP transpeptidases.
MRSA
Methicillin-resistant Staph aureus
There’s Penicillin-resistant
Strep pneumonia
These Penicillins are most prescribed by dentists.
Natural Penicillins (Pen V and Pen G)
Which natural Penicillin is better orally?
Pen V bc Pen G is acid labile.
For serious infections of oral anaerobes that have beta lactamases, which antibiotic is best?
Clindamycin.
These Penicillins are used more for their better absorptoin and long half-life with similar activity to Penicillin.
Amino penicillins, like Amoxicillin
Penicillin used commonly for prophy for endocarditis.
Amoxicillin (2g 1 hr prior to invasive dental procedure).
Not a good anti-Staphylococcal drug and is still degraded by beta lactamases.
Amoxicillin
Anti-Staphylococcal Penicillin
Nafcillin
Amino Penicillin
Amoxicillin
Extended spectrum Penicillin
Piperacillin
If allergic to Penicillin, can get this.
Desensitization
Adverse effect of Methicillin allergy
Interstitial nephritis
A beta lactamase inhibitor.
Clavulonic acid
Bind irreversibly to beta lactamases, and act as “suicide inhibitors” and cause destruction of enzymes.
Beta lactamase inhibitors.
Beta lactamase inhibitors have the greatest activity against what kind of oral bacteria?
Gram + anaerobes.
This oral formulation is given when a dental infection won’t go away with Penicillin.
Amoxicillin and Clavulonic acid
This is most commonly prescribed for serious dental infections.
Clindamycin
Often used bc it’s not affected by beta lactamases.
These antibiotics have a beta lactam ring and also attack the cell wall of bacteria.
Cephalosporins
Bacterial cell wall-active agents.
Penicillin
Cephalosporins
A really bad thing about Cephalosporins.
Have a big chance of being allergic to Cephalosporins if you’re allergic to Penicillin.
Cephalosporins CANNOT be used in these people.
People allergic to Penicillins.
Can you take Aztreonam if you’re allergic to Penicillin?
Yes! There’s NO Cross-reactivity
Bacteria that have these are resistant to carbepenems.
Metallo-beta lactamase-Zn
Always given with Cilistatin
Imipenem
Binds to D-ala-D-ala to inhibit transglycosylation.
Vancomycin
Location of Vancomycin binding on the bacterial cell wall.
Terminal D-ala-D-ala.
Type of bond between Vancomycin and D-ala-D-ala
Electrostatic
Type of bacteria that Vancomycin kills.
Gram positive aerobes and anaerobes.
“In the van we have: ….”
Positive aerobes and anaerobes.
Is Vancomycin used for the prophylaxis of endocarditis?
NEVER
If Vancomycin is taken this way, it’s causes pseudomembranous colitis.
Orally
What occurs with rapid administration (less than 1 hr for 1 gram dose) of Vancomycin?
Severe histamine reaction and “Red Man” or “Red Neck Syndrome.”
Older preparations of Vancomycin were what?
Impure and caused nephrotoxicity.
Newer formulations of Vancomycin carry little increased risk of this.
Nephrotoxicity.
