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Flashcards in 6 - Antibiotics Deck (24)
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1
Q

What are the different ways that anti-bacterial agents can be classified?

A
2
Q

What questions should be asked when choosing an antibiotic?

A
  • Is it active against the target organism?
  • Does it reach site of infection?
  • Is it available in right formulation?
  • Does it interact with other drugs?
  • What is the half life? (dosing)
  • Is there toxicity issues?
  • Does it need therapeutic drug monitoring?
  • Is patient allergic?
3
Q

What are the different mechanisms of actions of antibacterials and outline a few classes of each?

A
4
Q

What are some ways of working out the right does of an antibiotic?

A
  • Find the minimum inhibitory concentration, e.g E test, disc test, broth microdilution
5
Q

What is the exact mechanism of action of penicillin and vanomycin?

A

Penicillin: Block penicillin binding protein binding site that normall causes cross linking in cell wall

Vanomycin: Sits on peptidoglycan residue that normally binds to the penicillin binding protein so it can no longer bind

6
Q

What are the different types of bacterial resistance?

A

Intrinsic: Never was sensitive to antbiotic

Adaptive: antibiotic given not high enough concentration to kill bacteria but enough to switch on genes that confer resistance

7
Q

What are some mechanisms of antibacterial resistance?

A

- Drug inactivating enzymes, e.g beta-lactamases

- Altered target for antibiotics so lower affinity, using enzymes

- Altered uptake, lower permeability, increase efflux

- Mutation of targets

8
Q

What is horizontal gene transfer?

A

Way that bacteria can share their resistance genes

9
Q

What are the different classes of beta-lactams?

A
10
Q

What are some examples of beta-lactams and what are they effective against?

A
11
Q

When are cephalosporins used and give an example of this type of drug?

A
12
Q

When are carbapenems used and give a few examples of them?

A
13
Q

What are a few examples of glycopeptide antibacterials?

A

- Teicoplanin: Similar to vanomycin, only needed once a day

- Vancomycin: Most G+ve, IV (apart from clos.diff where oral), Therapeutic drug monitoring, resistance rare in staphs but common in enterococci

14
Q

What are some examples of tetracycline and what are they used for?

A
  • Doxycycline and Tetracycline
  • Can’t be fiven to pregnant or breastfeeding women either as stain developing teeth of babies yellow
15
Q

What is an example of an aminoglycoside and what is it used for?

A

- Gentamycin

  • Therapeutic drug monitoring needed
  • Potentially nephro/ototoxic so be careful in patients with renal issues
  • Reserved for gram neg sepsis
16
Q

What are some examples of macrolides and what are they used for?

A
  • Erythromycin and clarithromycin
17
Q

What is an example of a quinalone and what is it’s action?

A
  • Ciprofloxacin
  • Associate with tendinitis, aortic dissection and CNS effects
18
Q

Describe the use of trimethoprim.

A
  • Inhibits folic acid synthesis
  • Used for UTI’s
  • Can be combined with sulphamethoxazole to help against MRSA and pneumocystis jirovecii
19
Q

What are the two types of antifungals and some examples of each?

A

Azoles:

  • Inhibit cell membrane synthesis
    • Fluconazole:* treat candida
    • Posaconazole:* active against apergillus

Polyenes:

  • Inhibit cell membrane function
    • Nystatin:* Topical candida
    • Amphotericin:* IV treatment of systemic fungal infections
20
Q

What are some examples of antivirals?

A
  • Aciclovir
  • Osteltamivir
  • Specialist agents for HIV
21
Q

How does aciclovir work?

A
22
Q

How does oseltamivir work?

A
23
Q

Describe the use of metronidazole.

A
  • Antibacterial and antiprotozoal agent
24
Q

What are the three different definitions of anti-microbial resistance?

A