Bacterial cell wall synthesis inhibitors Flashcards
Recall some of the key information covered in this topic on bacterial cell wall synthesis inhibitors
Name 2 classes of bacterial cell wall synthesis inhibitors.
Beta-lactams, Glycopeptide
Beta lactams bind to the active site 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, flucloxacillin),
- 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
Are natural penicillins commonly used against Staphylococcus aureus?
No
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 are the penicillins mainly cleared?
Renal clearance
Name the 2 aminopenicillins
Ampicillin, amoxicillin
Are aminopenicillins effective against beta lactamase producing strains of bacteria?
No
Which of the aminopenicillins (amoxicillin or ampicillin) has better oral absorption?
Amoxicillin
Does aminopenicillins sufficiently cover Pseudomonas and Klebsiella?
No
How are aminopenicillins cleared?
Renal excretion
How is piperacillin administered?
Intravenously
Which class of penicillins has coverage against Pseudomonas, Proteus and Klebsiella?
Anti-pseudomonal penicillins (piperacillin)
Name 3 beta lactams-beta-lactamase inhibitor combination drugs.
- Augmentin (Amoxicillin + clavulanic acid)
- Unasyn (ampicillin + sulbactam)
- Zosyn (piperacillin + tazobactam)
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 a microbe that commonly causes nosocomial infections and is resistant to all penicillins.
MRSA (methicillin resistant Staphylococcus aureus)
Name at least 2 penicillins related life-threatening allergic reactions.
- Anaphylaxis
- Stevens Johnson syndrome
- Toxic epidermal necrolysis