Antibiotics ✅ Flashcards
What groups can antibiotics be divided into?
- Beta-lactam agents
- Macrolides
- Tetracyclines
- Aminoglycosides
- Glycopeptides
- Fluoroquinolones
What can beta-lactam agents be further divided into?
- Penicillins
- Cephalosporins
- Carbapenums
Give 4 examples of penicillins
- Penicillin
- Flucloxacillin
- Amoxicillin
- Piperacillin
Give 2 examples of cephalosporins
- Ceftriaxone
- Cefuroxime
Give 2 examples of carbapenums
- Meropenum
- Imipenum
Give 3 examples of macrolides
- Erythromycin
- Azithromycin
- Clarithromycin
Give an example of a tetracycline
Doxycycline
Give 2 examples of an aminoglycoside
- Gentamicin
- Amikacin
Give 2 examples of glycopeptides
- Vancomycin
- Teicoplanin
Give an example of a flouroquinolone
Ciprofloxacin
What does pharmacokinetics describe?
The change in drug and metabolite concentrations in the body over time
What does pharmacodynamics consider?
The concentration of a drug at the site of action and the effect it produces on that site, both in terms of clinical effect and adverse effects, at different concentrations
Why is it important to understand pharmacokinetic-pharmacodynamic profiles for antimicrobial drugs?
It guides dosage and dose frequency
What factors decide dose frequency of antibiotics?
- Half life
- Mechanism of action of antibiotic
Give an example of an antibiotic with a short half life
Penicillins
What is the implication of an antibiotic having a short half life?
It needs to be given more frequently
Give an example of an antibiotic with a very long half life?
Azithromycin
What aspect of a drugs mechanism of action is important when considering dosing intervals?
The way the activity of a drug is affected by it’s concentration
In what ways may the activity of a drug be affected by it’s concentration?
- Activity may be related to time drug exceeds the minimum inhibitory concentration (MIC)
- Activity may be related to the peak antibiotic concentration reached
Give an example of an antibiotic whose activity is related to the time that the concentration exceeds the minimum inhibitory concentration
Penicillin
Give an example of an antibiotic whose activity is related to the peak antibiotic concentration
Gentamicin
What does the therapeutic index of a drug describe?
How likely the drug is to cause toxicity to the host
How is the therapeutic index of a drug calculated?
The maximum tolerated dose divided by the minimum effective dose
What is the minimum effective dose of an antibiotic determined by?
The lowest dose that will give the required MIC at the site of infection
Give an example of class of antibiotic with a high therapeutic index
Beta-lactam agents
What is required for antibiotics with a low therapeutic index?
Serum level monitoring and dose adjustment
Give an example of a class of antibiotics with a low therapeutic index
Aminoglycosides
What are the ways that antibiotics can exert their antimicrobial effects?
- Disruption of bacterial cell wall
- Inhibition of protein synthesis
- Inhibition of DNA replication
- Interruption of microbial chemical pathways
What classes of antibacterial agents exert their actions by disruption of the bacterial cell wall?
- Beta-lactams
- Glycopeptides