Antibitotics - Cell wall Flashcards
Which antibiotics work on the cell wall?
Carbapenems
Cephalosporins
Antiseuodmonal Penicillins
Monobactams
Penicillins
How do penicillins work?
Penicillin inhibits the enzyme responsible for cross-linking of peptidoglycans. Enzymes are called transpeptidation (DD-transpeptidase) work to tighten the small and make it a secure structure.
Some germs, such as Escherichia coli (E. coli) and Klebsiella, produce an enzyme. This enzyme inactivates penicillins and cephalosporins, making the germ harder to treat with antibiotics.
What is this enzyme called?
What is an effective inhibitor of beta-lactamase enzymes?
Beta-Lactamase
Clavulanic Acid inhibits Beta lactamase
What penicillins are effective against Beta-lactamase and why?
- Flucloxacillin - Has an acyl side chain that protects the B-lactam ring.
- Co-amoxiclav - Combined amoxicillin and clavulanic acid.
- Tazocin - Combined Piperacillin and Tazobactam which is a B-lactamase inhibitor.
What antibitotic is reserved for severe psuedomonal infections ?
Tazocin
Name a cephalosporin
- Cefuroxime
- Cefotaxime
What antibiotics have reduced sensitivity to the b-lactamase enzyme ?
- penicillin
- Cephalosporins
What cephalosporin can treat MRSA skin infections such as cellulitis ?
5th gen - Ceftaroline fosamil
Explain how carbapenems work
The carbapenems are B-lactam antibiotics like the cefalosporins but can inhibit B-lactamase enzymes directly.
Name a carbapenem
Meropenem
Explain how monobactams work
Mediated by inhibition of penicillin-binding protein 3 (PBP3), interfering with peptidoglycan synthesis and cell division
What is the only monobactam
- Aztreonam
When is monobactams typically used ?
- its uses include delivery by inhalation to treat Pseudomonas A infections in patients with cystic fibrosis.
- IV/IM/inhaled dosage forms
