M13 - Antibiotics Flashcards
What are antibiotics?
Small molecules that kill/ inhibit the growth of prokaryotes/ bacteria.
The ability of bacteria to escape the action of antibiotics is known as?
Antibiotic resistance
What can antibiotics target?
- cell walls
- DNA replication
- DNA gyrases
- Metabolic pathways
- cell membranes
What family of antibiotic contains B-lactam ring?
The Penecillins
What makes penicillin variable?
flexible molecule
side groups and chains
Where is penicillin secreted?
Kidneys
Is penicillin safe in pregnancy?
Yes
When should you not prescribe penicillin?
in presence of mononucleosis infection
Where is Penicillin V absorbed?
Intestine
Why has Penicillin V got less impact on GI tract?
wide spectrum
Why should you take Penicillin 30 minutes before a meal or 3 hours after?
It is sensitive to stomach acid
When does Penicillin plasma concentration peak?
30-60 minutes after taking
Amoxicillin is stable/ unstable in the presence of stomach acid?
Stable
When does Amoxicillin plasma concentration peak?
60-120 minutes after taking
What is co-amoxiclav?
Amoxicillin and clavulanic acid
What is the role of clavulanic acid?
inhibits action of beta lactamase
what enzyme does clavulanic acid inhibit?
Beta lactamase
What are erythromycin, clarithromycin, and azithromycin examples of?
Macrolides
What type of antibiotics are macrolides?
lipophilic
Is erythromycin safe/ unsafe in pregnancy?
safe
What are lincomycin and clindamycin examples of?
Lincosamides
What is the mode of action of lincosamides?
bind to 50S ribosome and block peptidyl transferase, preventing peptide bond synthesis
What are lincosamides used for?
severe/ deep staph infections
What are minocycline and doxycycline examples of?
Tetracyclines
What is the mode of action of tetracyclines?
bind to 30S subunit and prevent attachment of tRNA to acceptor sites and stops chain elongation.
What main infection are tetracyclines used to treat?
Chlamydia
Are tetracyclines safe in pregnancy?
No
What antibiotic is used to treat dry socket?
Metronidazole
What type of cells cause biofilms to exclude antibiotics ?
Persistor cells
What are persistor cells?
cells that resist treatment and become tolerant by changing to state of dormancy
What type of resistance affects almost all species strains and exists before antibiotic use?
Natural
What type of resistance affects a fraction of strains and is increased with antibiotic use ?
Acquired resistance
In what way can a resistance gene be passed within and between species?
Horizontal gene transfer
What are the 3 stages of antimicrobial stewardship?
- what to prescribe
- whether to prescribe
- for how long to prescribe
What bacteria do antibiotics pose a risk to?
C. difficile
What are the 4 C broad spectrum antibiotics?
- Cephalosporins
- Co-amoxiclav
- Ciprofloxacin
- Clindamycin