Brainscape's Knowledge GenomeTM

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


See full index

Infectious diseases > Antibiotics > Flashcards

Antibiotics Flashcards

Penicillin Cephalosporins Carbapenems Macrolides Aminoglycosides Lincosamides Glycopeptides Tetracyclines Sulfonamides

1
Q

How do organisms become resistant to beta lactam antibiotics?

A
  1. Alter target site of penicillin binding protein (PBP)
    A. Decrease affinity of PBP fo antibiotic by - modifying existing PBP i.e. create mosaic PBP (penicillin resistant strep pneumonia)
    - Mutation of structural gene of PBP (amp resistant Haemophilus
    B. Import new PBP (mecA in MRSA)
  2. Destroy beta lactam antibiotic
    A. Increase production of beta lactamase (most common reason. Overcome by using in combination i.e. augmentin/timentin.)
    - acquire more efficient promoter
    - deregulate control of beta lactamase
    B. Modify structure of resident beta-lactamase (extended spectrum klebsiella
    C. Import new beta lactamase with different spectrum of activity
  3. Decrease concentration of beta lactam antibiotic inside cell by
    - Loss of porin ->restrict entry
    - pump it out
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Name 2 1st generation cephalosporins. What are there activity of action.

A

cephazolin
cephalexin
Usually gram positive (staph/strep)

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

Name 2 2nd generation cephalosporins.

A

Cefuroxime
Ceclor
Better activity against gram negative

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

What name 3 3rd generation cephalosporins.

A

cefotaxime
ceftriaxone
ceftazidime (good against pseudomonas)

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

Name 1 4th generation cephalosporin.

A

cefepime (good for pseudomonas + MRSA)

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

What is the action of glycopeptides? Name 2 examples

A

Vancomycin
Teicoplanin
Bacericidal and act via inhibition of cell wall synthesis.

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

Name 3 aminoglycosides.

A

Gentamicin, tobramycin, amikacin

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

What are side effects of aminoglycosides?

A

Ototoxicity - especially in mitochondrial DNA mutation (A1555G). High tone hearing loss. Irreversible in 50%.
Nephrotoxicity.
NM blockade

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

How does chloramphenicol work? What are its side effects?

A

Broad spectrum protein synthesis inhibitor.
Causes gray-baby syndrome, bone marrow suppression, aplastic anemia
- need to monitor Hb, Fe.
Interacts with phenytoin, phenobarb, rifampicin.

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

What class of drug is clarithromycin? What are some side effects?

A

Macrolide.
Same S/E as erythromycin (but less)
GI upset, dyspepsia.
Drug interactions same as erythromycin

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

What are side effects of doxycycline?

A

Teeth staining. (avoid under 8)
GI upset, photosensitivity.
Interacts with aluminium, calcium, mg ,zinc, iron containing products. Food/dairy can decrease absorption

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

Why are certain aminoglycosides contraindicated in anaesthetics?

A

Blocks NM junction (avoid with botulism poisoning)

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

How do tetracyclines work?

A

Bacteriostatic. binds to bacterial 30s ribosomal subunit - inhibit protein translation.

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

What are complications of tetracyclines?

A

eosinophilia, leukopenia, thrombocytopenia, pseudotumour cerebri, anorexia, emesia dn nausea, hepatitis, superinfection, hypersensitivity reaction.

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

How do sulfonamides work?

A

Bacteriostatic that inhibit bacterial folate synthesis pathway.

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

What is an example of sulfonamide and side effects?

A

Trimethoprim
Macrocytosis
Myelosuppresion.

17
Q

What class of drug is linezolid? What is the most common side effect of linezolid? What are others?

A

Oxazolidinone - binds to 50s ribosome subunit 70s ribosome subunit formation

Myelosuppresion. (worse with renal dysfunction)

C. Diff colitis, nausea, diarrhoea, headache, peripheral/optic neuropathy.

18
Q

How do macrolides work?

A

Binds to 50S subunit of bacterial ribosome - block in elongation of bacterial polypeptides.
ie clarithromycin, azithromycin, erythromycin.

19
Q

What should you watch out for in macrolides?

A

DRUG INTERACTION (CYP3A4) - especially erythromycin (less with clarithromycin and azithromycin)

20
Q

What medication used together with macrolide can increase its levels?

A

itraconazole

21
Q

What happens to erythromycin level when it is used with carbamazepine or phenytoin?

A

Decreases

22
Q

Name a lincosamide and how it works.

A

Clindamycin. (lincomycin)
Interferes with protein synthesis by binding to 23S portion of 50S ribosome to cause premature dissociation of peptidyl tRNA. Bacteriostatic.

23
Q

What is the main indication of lincosamides?

A

MRSA. Invasive group A strep and anaerobe infections with beta lactam.

24
Q

How do fluoroquinolones work? Name some examples.

A

Inhibit bacterial DNA replication by binding to the topoisomerase of the target pathogen, inhibiting DNA gyrase.

25
Q

What organisms do linezolid target?

A

Gram positives - MRSA, VRE.

No effect against gram negatives.

26
Q

How do aminoglycosides work?

A

Binds irreversibly to 30s ribosome subunit and cause cell membrane damage. Concentration dependent bacteriocidal effect.

27
Q

How do cephalosporins work?

A

Binds to penicillin binding proteins, interfering with cell wall glycopeptidoglycan synthesis. Bacteriacidal.

28
Q

What are side effects of cephalosporins

A 
Like beta lactams - DRESS, rash.
With high dose:
Nephrotoxicity
Neurotoxicity
Neutropenia
29
Q

What is the most common side effect of vancomycin?

A

Phlebitis.

Others: Red man syndrome, neurotoxicity, nephrotoxicity, bone marrow suppression, ototoxicity.

30
Q

Which antiepileptic should you watch out for with carbapenem usage?

A

Valproate (levels might drop)

31
Q

What are adverse effects with carbapenem use?

A

Neurotoxicity
Phlebitis (most common)
Nausea + vomiting

32
Q

How does rifampicin work?

A

Rifampicin (derivative of rifamycin B) and rifabutin (derivative of rifamycin S) inhibit bacterial RNA polymerase. They are bactericidal against rapidly dividing M. tuberculosis and active against those which are semi-dormant (intracellular organisms).

33
Q

Which group of bugs are resistant to amoxycillin, augmentin and all cephalosporins?

A

ESCAPPM group

Enterobacter spp., Serratia spp., Citrobacter freundii, some strains of Acinetobacter spp., Aeromonas spp., Proteus vulgaris and P. penneri, Providencia spp., Morganella morganii, other Gram-negative bacilli with chromosomal AmpC

34
Q

How does metronidazole work?

A

Disrupts DNA synthesis.

35
Q

What are side effects of metronidazole?

A

n+v
metallic taste in mouth.
Neurotoxicity
thrombocytopenia, leukopenia

Infectious diseases (7 decks)

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