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Flashcards in Principles of Anti-Bacterial Chemotherapy Deck (87)
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1
Q

When should anti-bacterial agents ideally be chosen?

A

After the infecting organism has been identified, and the results of susceptibility tests are available

2
Q

How long does it commonly take for results of tests investigating organism type and susceptibility to develop?

A

24-48hours

3
Q

What is the result of tests into organism type and susceptibility taking 24-48 hours to develop?

A

Empirical treatment is often initially started

4
Q

What is empirical treatment of bacterial infections based on?

A

Clinical insight and epidemiological data

5
Q

What can happen once the infecting organism has been identified?

A

Organism-based therapy can start

6
Q

What are bactericidal agents?

A

Those able to kill bacteria directly

7
Q

What are bacteriostatic agents?

A

Those that inhibit bacterial growth and require the immune system to eliminate the remaining pathogens

8
Q

How can the types of antibiotics be grouped together for classification?

A
  • Penicillins
  • Cephalosporins
  • Monobactams
  • Carbapenums
  • Tetracyclines
  • Aminoglycosides
  • Macrolides
  • Metronidazole
  • Sulphonamides
  • Trimethroprim
  • Vancomycin
  • Teicoplanin
9
Q

What kind of antibiotics are the penicillins?

A

Bactericidal

10
Q

What do the penicillins contain?

A

A ß-lactam ring

11
Q

How do the pencillins act?

A

By interfering with the peptioglycan cell wall production, inhibiting the action of transpeptidase

12
Q

How well do pencillins diffuse?

A

Well though bodily tissues, poorly into cerebrospinal fluid

13
Q

When will penicillin diffuse well into cerebrospinal fluid?

A

When meninges are inflamed

14
Q

What % of the population are allergic to penicillins?

A

1-10%

15
Q

Give 6 examples of pencillins

A
  • Benzylpenicillin
  • Phenoxymethylpenicillin
  • Flucloxacillin
  • Ampicillin
  • Amoxicillin
  • Piperacillin
16
Q

What is benzylpenicillin also known as?

A

Penicillin G

17
Q

What is benzylpenicillin important for?

A

Important antibiotic against streptococcal infection and many other bacteria

18
Q

How must benzylpenicillin be administed?

A

Via IV

19
Q

Why must benzylpenicillin be given via IV?

A

It is inactivated by gastric acid

20
Q

What is phenoxymethylpenicillin also known as?

A

Penicillin V

21
Q

How is phenoxymethylpenicillin similar to benzylpenicillin?

A

It has a similar antibacterial spectrum

22
Q

How does phenoxymethylpenicillin differ from benzylpenicillin?

A

It is not inactivated by gastric acid

23
Q

How is phenoxymethylpencillin administed?

A

Orally

24
Q

What is phenylmethylpenicillin used for?

A
  • Respiratory tract infections in children
  • Streptococcal tonsillitis

Not used against serious infections

25
Q

What is flucloxacillin resistant to?

A

Penicillinases

26
Q

What is the result of flucloxacillin being resistant to penicillinases?

A

It is acid stable

27
Q

What is flucloxacillin used against?

A

Streptococcal infections

28
Q

What kind of antibiotics are ampicillin and amoxicillin?

A

Broad spectrum

29
Q

What can ampicillin be used for?

A

Most gram positive and gram negative bacteria

30
Q

What is amoxicillin used for?

A

Similar purposes as ampicillin, but also for prophylaxis for endocarditis

31
Q

What is co-amoxiclav?

A

A mixture of amoxicillin and clavulanic acid

32
Q

What is clavulanic acid?

A

A ß-lactamase inhibitor

33
Q

What does co-amoxiclav do?

A

Makes amoxicillin effective against ß-lactamase bacteria

34
Q

What kind of antibiotic is piperacillin?

A

Extended spectrum

35
Q

What can piperacillin be used as?

A

An antipseudomonal activity

36
Q

What kind of antibiotics are cephalosporins?

A

Broad spectrum

37
Q

What are cephalosporins closely related to?

A

The penicillin group

38
Q

What are cephalosporins used for?

A

Used in the treatment of;

  • Septicaemia
  • Meningitis
  • Peritonitis
  • UTIs
39
Q

How well do cephalosporins diffuse?

A

Diffuse well through body, but cannot enter the CSF (unless the meninges are inflamed)

40
Q

What is seen with long term cephalosporin treatment?

A

Antibiotic associated colitis

41
Q

Why is antibiotic associated colitis seen with long term cephalosporin treatment?

A

Due to the broad spectrum nature of the antibiotic

42
Q

How many generations are there of cephalosporins?

A

5

43
Q

What are the important generations of cephalosporins?

A
  • Cefotaxim
  • Ceftazidime
  • Ceftriaxone
44
Q

What is cefotaxim used against?

A

Gram-negative bacteria

45
Q

What is ceftazidime good for?

A

Good activity against pseudomonas

46
Q

What is ceftriaxone used for?

A
  • Serious septicaemias
  • Pneumonias
  • Meningitis
47
Q

What are monobactams?

A

Monocyclic beta-lactams

48
Q

What are monobactams used against?

A

Gram negative bacteria of pseudomonas, Neisseria meningitidis, and Haemophilus Influenzae

49
Q

What is the main monobacteum?

A

Aztreonam

50
Q

How is aztreonam given?

A

Intravenously

51
Q

How are carbapenums given?

A

Intravenously

52
Q

What kind of antibiotics are carbapenums?

A

Broad spectrum

53
Q

What are carbapenums used against?

A

Aerobic and anaerobic Gram positives and negatives

54
Q

What do carbapenums have a similar mechanism of action to?

A

Other beta-lactams

55
Q

What kind of antibiotics are tetracyclines?

A

Broad spectrum

56
Q

What has happened to tetracyclines activity?

A

It has decreased

57
Q

Why has tetracyclines activity decreased?

A

Due to increased bacterial resistance

58
Q

What are tetracyclines used against?

A
  • Chlamydia
  • Ricketts
  • Mycoplasma
59
Q

How do tetracyclines work?

A

By interfering with protein synthesis in the bacteria and lock the tRNA and the septal site of the mRNA molecule

60
Q

What is the most used tetracycline?

A

Doxycycline

61
Q

Give two examples of aminoglycosides?

A
  • Streptomycin
  • Gentamicine
62
Q

How do aminoglycosides work?

A

By preventing the translation of mRNA into protein

63
Q

Are aminoglycosides bactericidal or bacteriostatic?

A

Bactericidal

64
Q

What kind of antibiotics are aminoglycosides?

A

Quite broad spectrum

65
Q

How are aminoglycosides given?

A

Injection

66
Q

Why must aminoglycosides be given by injection?

A

Because they are not absorbed by the gut

67
Q

What is the problem with aminoglycosides?

A
  • They are nephrotoxic in high concentrations
  • They can damage cranial nerves
68
Q

What is gentamycin widely used as?

A

The treatment of choice for many serious bacterial infections

69
Q

What is the most commonly used macrolide?

A

Erythromycin

70
Q

What is the action of erythromycin similar to?

A

Penicillin

71
Q

What is erythromycin used for?

A
  • Alternative to penicillin in penicillin-allergic patients
  • Respiratory infections
  • Some penicillin resistant staphylococcus
72
Q

What is the problem with erythromycin?

A

It has numerous side effects, even in low doses

73
Q

What are the side effects of erythromycin?

A
  • Nausea
  • Vomiting
  • Diarrhoea
74
Q

What kind of drug is metronidazole?

A

Antimicrobal

75
Q

What does metronidazole have high activity against?

A

Anaerobic bacteria and protozoa

76
Q

What is metronidazole used for?

A
  • Pseudomembranous colitis
  • Surgical and gynaecological sepsis
77
Q

What has happened to the clinical use of suphonamides and trimethroprim?

A

It has reduced

78
Q

Why has the clinical use of sulphonamides and trimethroprim reduced?

A

Resistance has been increased towards them

79
Q

What are sulphonamides and trimethroprim used together with?

A

Trimoxazole

80
Q

Why are sulphonamides and trimethroprim used with trimoxazole?

A

For their synergistic action

81
Q

What is the problem with using sulphonamides and trimethroprim together with trimoxazole?

A

Can cause serious side effects

82
Q

What is trimethoprim used for?

A

UTIs and RTIs

83
Q

What kind of antibiotics are vancomycin and teicoplanin?

A

Glycopeptides

84
Q

Are vancomycin and teicoplanin bactericidal or bacteriostatic?

A

Bactericidal

85
Q

What are vancomycin and teicoplanin used against?

A

Aerobic and anaerobic Gram positive bacteria. Can be used against multi-resistant S. Aureus

86
Q

How well is vancomycin absorbed?

A

Poorly

87
Q

What is the result of vancomycin being poorly absorbed?

A

It is only given orally for a psuedomembranous colitis