Bacterial cell wall synthesis inhibitors Flashcards
Name 2 classes of bacterial cell wall synthesis inhibitors.
Beta-lactams, Glycopeptide
Beta lactams bind to the active side of which enzyme?
Transpeptidase (penicillin binding protein)
Name 4 types of beta lactams
Penicillins, cephalosporins, carbapenems, monobactam
Name the 4 classes of penicillins
natural penicillins (Pen G and Pen V),
penicillinase resistant penicillins (cloxacillin),
aminopenicillins (amoxicillin, ampicillin),
antipseudomonal penicillins (piperacillin)
Which natural penicillin is administered parenterally?
Penicillin G
Syphilis caused by Treponema pallidum can be treated with which penicillin?
Penicillin G
Which natural penicillin is administered orally?
Penicillin V (not IV)
Which bacteria are natural penicillins effective against?
Mostly against Gram positive (streptococci and bacillus diphtheriae)
And some gram negative (meningococci and gonococci)
beta-lactamase negative strains
What is cloxacillin effective against?
It is a Penicillinase-resistant Penicillin (anti-staphylococcal Penicillin)
effective against Penicillinase producing staphylococci and other gram positive.
Ineffective against Gram negative
What are Ampicillin and amoxicillin effective against?
have additional hydrophilic group, allowing penetration into Gram-negative bacteria
Also effective against many beta-lactamase negative strains of Gram negative/positive microorganisms
What are Ampicillin and amoxicillin ineffective against?
Pseudomonas and Klebsiella
How is piperacillin administered?
Intravenously
Which class of penicillins has coverage against Pseudomonas, Proteus and Klebsiella?
Anti-pseudomonal penicillins (piperacillin)
How are penicillins cleared?
Renal excretion
Which of the aminopenicillins (amoxicillin or ampicillin) has better oral absorption?
Amoxicillin
Are aminopenicillins effective against beta lactamase producing strains of bacteria?
No
Name the 2 aminopenicillins
Ampicillin, amoxicillin
Which class of penicillin is commonly used against methicillin sensitive Staphylococcus aureus?
Penicillinase resistant penicillins
How does methicillin sensitive Staphylococcus aureus acquire resistance against the natural penicillins?
They produce penicillinases
Which bacteria is cloxacillin effective against?
Methicillin Sensitive Staphylococcus aureus (MSSA)
How do beta-lactamase inhibitors work?
They either covalently bind at or near the active site of the β-lactamase and restructures it, permanently inactivating. In doing so, they protects other beta-lactam antibiotics from beta-lactamase catalysis.
Name 3 beta lactams-beta-lactamase inhibitor combination drugs.
Augmentin (Amoxicillin + clavulanic acid)
Unasyn (ampicillin + sulbactam)
Zosyn (piperacillin + tazobactam)
Which beta-lactamase combination drugs can be administered orally?
Augmentin (Amoxicillin + clavulanic acid)