Brainscape's Knowledge GenomeTM

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


See full index

Applied Pharmacology bs > Antimicrobials, Antifungal and Antibiotics > Flashcards

Antimicrobials, Antifungal and Antibiotics Flashcards

1
Q

What are antibiotics effective on?

A

bacteria

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

What are the two ways in which antibiotics work on bacteria?

A

Bactericidal (killing bacteria)
Bacteriostatic (inhibiting/ arresting growth of bacteria)
* bacteriostatic antibiotics allow the immune system to act as well

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

Where can antibiotics act on the cell (these are why they do not effect the human cells and just the bacteria)?

A
  • the cell wall
  • inhibiting DNA biosynthesis
  • inhibiting RNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What allows us to classify bacteria in to catergories?

A
  • gram negative (pink)

- gram positive (purple)

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

What are the difference between bacteria that is gram positive compared to gram negative bacteria.

A

positive - the cell wall has thick peptidoglycan layer

negative - has a thin peptidoglycan layer. It has an outer membrane

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

What antibiotics act on the peptidoglycan layer?

A

penicillins
cephalosporins
carbapenems
vancomycin

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

Penicillins, cephalosporins, carbapenems and vancomycin all act on the peptidoglycan layer on bacteria. Why is vancomycin different.

A
  • it does not have the structural component of the beta lactam ring.
  • has a different mode of action
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are b-lactam antibiotics effective on?

A
  • against growing and dividing cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Are B-lactam antibiotics bactericidal or bacteriostatic?

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

How do resistant bacterial species act on B-lactam antibiotics

A

secrete enzyme (B-lactamase) which inactivates antibiotics by breaking down their B-lactam layer

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

How do B-lactam antibiotics act?

A
  • Inhibit the enzyme involved in the transpeptidase cross-linking reaction
  • interfere with linking the individual chains together
  • disrupt the peptidoglycan layer
  • leading to autolysis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are penicillin effective against?

A
  • very effective against gram positive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the problems with penicillin’s ?

A
  • some allergy reactions

- aminopenicillins better tolerated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are cephalosporins effective against?

A

1st generation - gram positive
2nd generation - anaerobes
3rd generations - gram negative
4th generations - pseudomonas

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

What are carbapenems effective against?

A
  • broad spectrum

- generally effective aginst all accept : MRSA and VRE

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

What are the problems with carbapenems ?

A

can only be administered by IV

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

What are the problems with vancomycin?

A

allergy reactions

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

How does vancomycin act?

A
  • still acts on the peptidoglycan layer

- but precludes peptidyl bridges

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

What is vancomycin effective against?

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

How is vancomycin administered?

A

IV

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

How is penicillin administered?

A

orally

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

other antibiotics target the RNA synthesis. What does this mean?

A
  • They are more universal as all bacteria have the same mechanism of RNA synthesis.
  • mostly basteriostatic, associated with greater toxicity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are examples of antibiotics which bind to and inhibit protein components of the 30s subunit?

A
  • tetracycline

- aminoglycosides (gentamycin, streptomycin)

24
Q

What are examples of antibiotics which bind to and inhibit protein components of the 50s subunit?

A
  • macrolides (erythromycin)

- chloramphenicol

25
Q

What is the different between the RNA of bacteria and human cells?

A

human cells are bigger

26
Q

What type of antibiotics inhibit DNA biosynthesis?

A

fluroquinolones

27
Q

What are examples of fluroquinolones which inhibit DNA biosynthesis?

A

all end in floxacin

28
Q

Which enzyme does floroquinolones inhibit?

A

DNA gyrase which is important to unwind DNA

29
Q

What are fluroquinolones effective against?

A

gram negative

- broad spectrum

30
Q

Rifampicin is used to treat what?

A

TB

31
Q

How does rifampicin act?

A

inhibits bacterial but not human RNA polymerases

32
Q

What is one way in which we can indirectly target nucleic acids biosynthesis?

A
  • by blocking biosynthesis of folic acid (by PABA)

- because we can not synthesis folic, we get it from our food

33
Q

What are examples of antibiotics that block folic acid biosynthesis?

A

sulphonamide
trimethoprim
co-trimoxazole ( a mixture of both)

34
Q

How do antibiotics become resistant?

A
  • decreased accumulation of the drug
  • reduced permeability of the drug
  • enzymatic inactivation of the drug (B-lactamase)
  • (mother to daughter or sideways to other species)
35
Q

Fungal diseases are know as mycoses. What are examples of superficial or systemic mycoses?

A 
superficial 
- scalp
- skin 
- oral cavity 
- vagina 
Systemic 
- affects internal organs (kidney, lungs, brain)
36
Q

Fungal cells are what type of cell?

A

eukaryotes

- opportunistic pathogens

37
Q

What puts patients at higher risk of developing fungal infections?

A 
- impaired immune system 
HIV/AIDs 
organ transplant 
if on long-term broad spectrum antibiotics 
premature birth 
cancer 
hospitalisation in ICU 
- menstrual cycle in women (vaginitis/thrush caused by C. albicans)
38
Q

What are the differences between fungal and human cells?

A
  • plasma membrane (Contain ergosterol in fungi)
  • cell wall (no cell wall in human cells)
  • Nucleus (DNA/RNA synthesis)
39
Q

How do echinocandins such as caspofungin and micafungi work?

A
  • inhibit B1,3 glucan synthesis

- these drugs are fungicidal

40
Q

Antifungals that act on ergosterol do to things what are these?

A
  • kill existing cells by binding to ergosterol in their plasma membranes
  • inhibit new cells by inhibiting ergosterol biosynthesis (Fungistatic)
41
Q

What do polyene antifungals do?

A
  • bind to ergosterol and form pores in plasma membrane

- causing leakage of cell constitutes

42
Q

What is the complication of prolonged use of polyene antifungals?

A

associated with severe side effects such as kidney failure

*because of the similarity between ergosterol and cholesterol

43
Q

What are the main examples of polyene antifungals?

A
  • amphotericin B

- nystatin

44
Q

Nystatin is a polyene antifungal what is it used to treat?

A
  • creams and lotion

- treat oral or GI fungal infections

45
Q

What is the polyene antifungal amphotericin B used to treat ?

A

only severe fungal infections due to its serious side effects such as kidney failure

46
Q

How do azoles act?

A
  • inhibit the enzymes lanosterol demethylase

- so block ergosterol biosynthesis and stops growth (fungistatic)

47
Q

There are two types of azoles what are they?

A
  • imidazoles (miconazole, clotrimazole and ketoconazole)

- triazoles ( fluconazole, voriconazole and itraconazole)

48
Q

What is the difference between imidazoles and triazoles?

A
  • imidazoles have two nitrate rings

- triazoles have 3 nitrate rings - more potent

49
Q

How do flucytosines work?

A
  • inhibit fungal DNA and RNA synthesis
50
Q

What are examples of allyamines?

A
  • terbinafine (Lamisil)

- amorolfine (curanail, loceryl, locetar)

51
Q

What are allyamines used to treat?

A
  • nail infections
52
Q

What are normally combined with flucytosines?

A

azoles

53
Q

What are flucytosines associated with ?

A
  • high levels of resistance
54
Q

How are resistance to antifungal drugs caused?

A
  • decreased accumulation of the drug (reduce permeability to drug)
  • inactivation of the drug
  • mutations in the drug targeting encoding genes
  • biofilm formation
55
Q

What are the high incidences of intrinsically resistance of antifungals?

A

azoles to candida species

Applied Pharmacology bs (10 decks)

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