Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PoD > Antimicrobial Chemotherapy > Flashcards

Antimicrobial Chemotherapy Flashcards

1
Q

MIC

A

Minimum inhibitory conc. of antimicrobial able to inhibit organism growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

MBC

A

Minimum antimicrobial conc. required to kill an organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Sensitive

A

Organism inhibited or killed by antimicrobial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Resistant

A

Organism not affected by antimicrobial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Bacteriocidal

A

Antimicrobial that kills bacteria - penicillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Bacteriostatic

A

Antimicrobial that inhibits bacteria growth - erythromycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Synergy

A

Combination of antimicrobials effect is greater than the sum of individual effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Antagonism

A

Combination of antimicrobials effect is less than the sum of individual effects - work against each other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Action of Antibiotics and examples

A

Inhibit cell wall synthesis - penicillin and cephalosporin
Inhibit protein synthesis - gentamicin and erythromycin
Inhibit nucleic acid synthesis - Trimethoprim and ciprofloxacin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Mechanism of inhibition of cell wall synthesis

A

B-lactams - inhibit peptidoglycan synthesis by inhibiting enzymes penicillin bind proteins (PBPs)

Glycopeptides - inhibit assembly of a peptidoglycan precursor - act only on gram positive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Mechanism of inhibition of protein synthesis

A

Structural difference of mammalian and bacterial ribosomes allow antimicrobial attach and alter function

Aminoglycosides - treatment of gram negative - coliform and Staph. are sensitive but strep. are not - gentamicin

Macrolide and tetracycline - treatment of gram positive if patient allergic to penicillin - erythromycin, clarithromycin (low MIC).
Staph. aureus, strep progenies, strep. pneumonia resistant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Mechanism of the inhibition of nucleic acid synthesis

A

Inhibit DNA directly or indirectly by disrupting precursors

Trimethoprim (treats UTI infect.) and sulphamethoxazole - used as a combo (co-trimoxazole) - chest infections

Fluroquinolones - ciprofloxacin treats gram negative and cannot be used in children (no cart. growth) and levoflaxocin treats gram positives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Polyene use and examples

A

Anti-fungal drugs that bind to ergosterol in fungal cell wall in yeasts and filamentous fungi. Bind to sterol in mammalian cell walls so toxic

Amphothericin B

  • IV treatment for serious yeast and fungal infections (use when necessary)
  • Very toxic - side effect: renal, hepatitis and cardiac toxicity

Nystatin

  • Regular use
  • Topical treatment or in oral suspension
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Azole and examples

A

Anti-fungal drugs that inhibit ergosterol synthesis

Fluconazole - only treats yeast infections and Candida albican sensitive but Candida krusei / glabrata are resistant

Intraconazole - yeast and filamentous fungi treats aspergillosis and dermatophytes

Vorinconazole - treats aspergillosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Characteristic and mechanism of anti-viral drugs

A

There are no virucidal drug (able to kill virus) but they are virustatic (inhibit growth and replication

Many are nucleoside analogues which disrupt nucleic acid synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Anti-Herpes drugs

A

Aciclovir - treats HSV and VZV and low toxicity

Famciclovir and Valaciclovir - HSV and shingles

Ganciclovir - CMW and toxic to bone marrow, given by IV (valganciclovir is a prodrug)

Foscarnet - treats HSV, VZV and CMW when they’re resistant to nucleoside analogues. High nephrotoxic and given by IV

Cidofovir - treat CMW

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Mechanism of anti-HIV drugs

A

Nucleoside analogue which disrupts reverse transcriptase - shows down replication

3 drug combo - two reverse transcriptase inhibitor and either non-one or protease inhibitor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Example of a non-nucleoside reverse transcriptase inhibitor and a protease inhibitor

A

Non - nevirapine and efavirenze

Prot - saquinavir, duranavir

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Drugs for Hep B and C

A

Hep B andC - interferon-a - forms host immune system and attaches to PEG so excretion is slowed and treatment is reduced

Subcutaneous injection of interferon a and oral ribacvarin treats hep C

Hep B - lamivudine given orally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Drugs for Viral Respiratory Infection

A

Zanamavir and oseltamivir - treats influenza A or B with 48hrs of symptoms and post-exposure prophylaxis

Ribavarin - nucleoside analogue treats severe Respiratory Syncytial Virus (RSV)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Allylamines and examples

A

Anti-fungal drug which suppress ergosterol but at different stage to azoles

Terbinafrine - dermatophyte infections; fungal infection of skin and nail

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Echinocandins and examples

A

Anti-fungal drug that inhibit synthesis of glucan polysaccharides in fungi

Caspogungin, micafungin and anidulafungin are fungicidal agents against serious candida and aspergillus infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Action of Benzyl Penicillin

A
  • B-lactam
  • Gram positive or meningococci
  • IV
  • Treats pneumococcal, meningococcal and strep. pyogenes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Actions of Amoxicillin and Ampicillin

A
  • B-lactam
  • Gram negative
  • 30% coliforms resistant
  • Streptococci and some coliforms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Action of Flucloxacillin (methicillin in lab)

A
  • B-lactam
  • Staphlococcal infections: resistant to staph. B-lactamase
  • MRSA is resistant
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Action of Piperacillin

A
  • B-lactam
  • Broad spectrum
  • Gram negative
  • Activity against enterococcus faecalis and pseudomonas species
  • Intra-adominal infection as anti-anaerobic activity
  • Combined with tazobactam = tazocin (B- lactamase inhibitor)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Action of Imipenem and Meropenem

A
  • B-lactam
  • Pen. subgroup Carbapenem
  • Widest spectrum
  • All bacteria, includ. anaerobes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Action of Ceftriaxone

A
  • Cephalosporin
  • 3rd gen with increased activity against gram neg
  • Active Pseudomonas spp.
  • Less activity to gram positive form first gen
  • Encourage C. Difficile
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Action of Aminoglycosides and give example

A
  • Inhibit protein synthesis
  • Gentamicin - toxic
  • Parenteral use only
  • Gram negative includ. pseudomonas
  • Staph sensitive but not strep.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Two examples glycopeptides and action

A
  • Inhibits cell wall synthesis
  • Vancomycin and Teicoplanin
  • Gram positive
  • Aerobic and anaerobic
  • Van. = toxic
  • Vancomycin resistent enterococci (VRE) - in enterococcus faecalis - precursor for peptidoglycan that it binds to have altered structure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Action of Macrolides

A
  • Inhibits protein synthesis
  • Gram positives
  • Alternative to penicillin to patients with pen. allergy
  • Activity against atypical pneumonia (legionella pneumophila)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Examples of macrolides

A

Clarithromycin and Erythromycin

-Azithromycin treats chlamydia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Action of Ciprofloxacin (Fluoroquinolone)

A
  • Inhibits nucleic acid synthesis by targeting enzymes involved in coiling DNA
  • Wide spectrum
  • Gram negative includ. pseudomonas
  • Second choice for staph infections
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Action of Levofloxacin (Quinolone)

A
  • Inhibits nucleic acid synthesis
  • Pneumococci
  • Atypical pneumonia
35
Q

Action of Metronidazole (miscellaneous)

A
  • Anaerobes
  • Gram pos and neg
  • Anaerobic infection; intra-abdominal sepsis
  • Treat MRSA
36
Q

Action of Fusidic acid (miscellaneous)

A
  • Anti-staphylococcal drug
  • Use in combo with flucloxacillin to prevent resistance
  • Diffuses well into bone and tissue - staph pneumonia
37
Q

Action of Trimethoprim (miscellaneous)

A
  • Inhibits nucleic acid synthesis by inhibiting purine synthesis
  • Treats UTIs
38
Q

Action of Tetracyclines (miscellaneous)

A
  • Broad spectrum which inhibit bacterial protein synthesis
  • Genital and respiratory tract infection
  • No to pregnant w. and -12yrs as deposited in teeth and bone
39
Q

Action of Clinamycin (miscellaneous)

A
  • Gram postive
  • Anaerobes
  • Good tissue penetration
  • Oral
  • Causes pseudo-membranous colitis
40
Q

Action of Linezolid (oxazolidinone)

A
  • Inhibits protein synthesis
  • Active against MRSA
  • Oral
  • Cause bone marrow suppression
41
Q

Action of Daptomycin (cyclic lipopeptide)

A
  • Inhibits protein synthesis
  • Gram positive only
  • Treats serious MRSA infection
42
Q

Action of Fidaxomicin

A
  • Macrocyclic antibiotic

- Bactericidal against C. difficile and reduces recurrence

43
Q

Name agents for urinary tract infection (cystitis)

A
  • Nalidixic acid

- Nitrofurantoin

44
Q

Action of Nalidixic acid

A
  • Quilones
  • Treats coliform urinary tract infect.
  • only gram neg. aerobes (coliform)
  • All excreted in urine
45
Q

Action of Nitrofurantoin

A
  • Urinary antiseptic - UTI treatment
  • Gram neg. - except Proteus and Pseudomonas spp.
  • Also some gram pos.
46
Q

What antimicrobials are associated with allergic reactions

A

Commonly B-lactam drugs

47
Q

Example of immediate hypersensitivity

A

Anaphylactic shock

48
Q

Mechanism of anaphylactic shock

A
  • After parenteral administration of drugs
  • IgE mediated
  • Itching, nausea, vomiting
49
Q

Symptoms of delayed hypersensitivity

A
  • Drug rashes
  • Uncommon: drug fever, serum sickness and erythema nodosum
  • Maculopapular and restricted to skin
50
Q

Gastrointestinal side effects

A
  • Nausea and vomiting

- Clostridium difficile

51
Q

What type of organism in C. difficile?

A

Anaerobic gram positive bacillus - spore forming

52
Q

How is C. difficile detected?

A

Detection of toxin in stool by an enzyme immunoassay (EIA)

53
Q

Steps taken when patient diagnosed with C. difficile?

A
  • Isolated until asymptomatic for 48hr

- Stop drugs if possible

54
Q

What is C. difficile treated with?

A

Oral metronidazole or vancomycin and fidaxomicin

55
Q

How do antimicrobials cause thrush?

A

Broad spectrum drugs suppress normal flora allowing overgrowth of Candida albicans causing oral/vaginal candidiasis (thrush)

56
Q

What side effect do antimicrobials have on the liver?

A
  • Cause hepatotoxicity
  • Elevation of enzymes
  • Hepatitis
57
Q

What drugs cause liver toxicity?

A
  • Tetracyclin
  • Rifampicin
  • Flucloxacillin
58
Q

What drugs cause nephrotoxicity (renal toxicity)?

A
  • Aminoglycoside (gentamicin, netilmicin, amikacin)

- Vancomycin

59
Q

What drugs cause Ototoxicity (neuro tox)

A

Aminoglycosides or vancomycin

60
Q

What can ethambutol (anti-tuberculous drug) cause?

A

Optic nerve damage

61
Q

What types of drugs cause encephalopathy and convulsions?

A

High dose penicillin and cephalosporin

62
Q

What drugs cause peripheral neuropathy?

A
  • Metronidazole

- Nitrofurantoin

63
Q

Neutropenia effect on haematological toxicity

A

Selective depression of one cell line in bone marrow

64
Q

Pancytopenia effect on haematological toxicity

A

Unselective depression of all bone marrow elements

65
Q

Linezolid effect on haematological toxicity

A
  • Bone marrow suppression

- Lowers platelet counts

66
Q

How to prevent adverse reactions

A
  • Use minimum dose and duration
  • Care with pregnant w., age and patients with liver or renal insufficiency
  • Monitor toxicity of drugs with small therapeutic margins
67
Q

Importance of age when choosing an antimicrobial agent?

A

Some not suitable for children - ciprofloxacin

68
Q

Importance of renal function when choosing an antimicrobial agent?

A

Doses to be decreased proportional to degree of renal insufficiency

69
Q

Importance of liver function when choosing an antimicrobial agent?

A

Doses decreased in hepatic insufficiency or use alternate drug

70
Q

Importance of pregnancy when choosing an antimicrobial agent?

A

Some drugs not used as mutagenic (in foetus) or teratogenic (cogenital abnormalities)

Unknown effect of foetus

71
Q

What are safe drugs to use in pregnancy?

A

Penicillins, cephalosporins and urinary antiseptic nitrofurantoin

72
Q

What drugs cause teratogenic and mutagenic effects?

A

Metronidazole and trimethoprim

73
Q

What is prophylaxis?

A

Administration of drugs to prevent the future occurrence of infection

74
Q

When is prophylaxis used?

A
  • Exposure to highly communicable disease

- About to undergo surgery that has high post-op infection rates

75
Q

What is a principle of prophylaxis?

A

Dosage should cover the period of risk only - beyond could develop resistant organisms

76
Q

What is empirical antimicrobial therapy?

A

Treating infection by guessing likely causative organisms and common drug susceptibility patterns

77
Q

What is important to carry out after empirical antimicrobials therapy?

A

Treatment to be reviewed once results of culture and antibiotic sensitivity tests are available

78
Q

Describe drug related considerations

A
  • Be effective against organism

- Choice based on results of sensitivity tests

79
Q

When should drugs be used in combination?

A
  • Cover mixed infections by more than one organisms
  • Synergistic effect
  • Minimise development of resistant strains to one agent
80
Q

Action of Co-amoxiclav

A
  • B-lactamase inhibitor

- Covers B-lactamase producing conforms (gram negative)

81
Q

Why monitor serum levels?

A

To ensure therapeutic levels have been achieved and to check it is not toxic

82
Q

What is the E test?

A

Way to measure MIC of drug against organism - can be read from the point where the growth of organism intersects strip

83
Q

What drugs treat C. difficile?

A

Oral metronidazole and vancomycin and fidaxomicin

84
Q

What drugs treat MRSA?

A

Vancomycin, teicoplanin, linezolid and daptomycin

PoD (35 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions