Antimicrobial agents: classes and MOA Flashcards
Name the dental antibacterial agents a dentist can prescribe?
amoxicillin
Azithromycin
Cefalexin
Clarithromycin
Co-amoxiclav
Doxycycline
Erythromycin
Metronidazole
Oxytetracycline
Phenoxymethylpenicillin
Sodium Fusidate
Tetracycline
Name the dental antifungal agents a dentist can prescribe?
fluconazole
miconazole
Name the dental antiviral agents a dentist can prescribe?
Aciclovir
where to find what drugs dentists can prescribe?
Dental practitioners formulary NICE
MOA of antibacterial to destroy/inhibit bacteria? (6)
- exploiting bacterial cells compared our our own cells
- Cell wall synthesis
- Protein synthesis.
- Nucleic acid synthesis.
- Folate synthesis.
- Disruption of the
cytoplasmic membrane.
natural form of penicillin?
benzyl-penicillin
example of anti-staphylococcal penicillin?
flucloxacillin
- type of beta-lactam and specifically a type of penicillin
Types of antibacterial agents targeting cell wall synthesis?
beta-lactam group of antibacterials
types of beta-lactams:
- penicillin’s
- cephalosporins
- carbapenems
- monobactams
gram positive vs gram negative bacteria?
2 main components of peptidoglycan layer of bacteria?
NAG and NAM
2 sugars alternating in the peptidoglycan layer of cell wall
what are penicillin binding proteins?
transpeptidases - catalyse the crosslinking of NAM and NAB sugars
NAG?
N-acetylglucosamine
NAM?
N-acetylmuramic acid
How does penicillin work?
- Transpeptidases (PBPs) are “tricked” use the beta-lactam as a “building block”.
- Acylation of the enzyme prevents further catalysis.
- Cell wall synthesis ceases followed by cell lysis.
What is the bacterial combat to penicillin?
beta-lactamases
b-lactamases hydrolyze the b-lactam ring of penicillins.
* Penicillins are unable to bind to their substrate.
How to pharma companies combat the b-lactamase of bacteria?
- Pharma fights back
- b-lactamase inhibitors e.g. clavulanic acid allows the partner antibiotic e.g. amoxicillin to continue binding to the substrate.
Clavulanic Acid: Inhibits many β-lactamases, often combined with amoxicillin (e.g., co-amoxiclav).
is the effect of antibacterial agents on protein synthesis bacteriolytic or bacteriostatic?
bacteriostatic effect
When would you use antibacterial such as: tetracyclines or erythromycin?
penicillin allergy
List the antibacterials that target cell wall synthesis
These antibiotics interfere with the synthesis of the bacterial cell wall, leading to cell lysis and death.
- Amoxicillin (Penicillin class): Cell wall synthesis inhibitor
- Cefalexin (Cephalosporin class): Cell wall synthesis inhibitor
- Co-amoxiclav (Combination of Amoxicillin and Clavulanic acid): Cell wall synthesis inhibitor (Amoxicillin part)
- Phenoxymethylpenicillin (Penicillin class): Cell wall synthesis inhibitor
List the antibacterials that target protein synthesis
These antibiotics inhibit bacterial protein synthesis by targeting bacterial ribosomes.
- Azithromycin (Macrolide class): Protein synthesis inhibitor
- Clarithromycin (Macrolide class): Protein synthesis inhibitor
- Doxycycline (Tetracycline class): Protein synthesis inhibitor
- Erythromycin (Macrolide class): Protein synthesis inhibitor
- Oxytetracycline (Tetracycline class): Protein synthesis inhibitor
- Sodium Fusidate: Protein synthesis inhibitor
List the antibacterials that target nucleic acid synthesis
These antibiotics inhibit bacterial DNA or RNA synthesis, leading to bacterial growth inhibition or death.
- Metronidazole: Nucleic acid synthesis inhibitor (interferes with DNA synthesis by forming toxic metabolites)
General mechanism of antibiotic resistance?
- enzyme production - beta-lactamases
- altering permeability
- alteration of the target site
- efflux pumps
- altered metabolic pathways (salvage) - shut down protein synthesis
antifungals and their cell membrane targets?
polyenes group of antifungals, target phospholipid bilayer
e.g. nystatin (topical)
azoles group of antifungals, target ergosterol
e.g. fluconazole
spectrum of activity?
narrow spectrum vs broad spectrum
broad spectrum if treating blindly
penicillin more narrow spectrum than amoxicillin
what bacteria is common in the mouth and what antibacterial would you use?
know it is strep, use penicillin, can kill off anaerobes also
and not broad spectrum amoxicillin
