SBM: Pharmacology & therapeutics - Antibiotics

Question 0

Examples of Structurally modified penicillins

Answer 0

Amoxicillin and ampicilling

Question 1

Mechanism of beta lactams (5)

Answer 1

They block the peptidoglycans synthesis
Beta lactams work against bacteria with PGN walls.
Does not work with chlamydia and mycoplasma.
They target penicillin binding proteins. (PBPs)These are transpeptidase enzymes which is involved in PGN synthesis.

Question 2

Treat chlamydia with beta lactam antibiotics? True ?

Answer 2

False

Question 3

Pencillin G is also called Benzylpenicillin. They are active against what bacteria ?

Answer 3

Streptococci
Staphylococci
Spirochaetes
Neisseria

Question 4

Pencillin G is also called Benzylpenicillin. They are NOT active against what bacteria

Answer 4

Enterobacteriaciae - because of PLPs and penicillinase

Question 5

And example of aminopenicillin is…

Answer 5

Amoxycillin

Question 6

Why are structurally modified pencillins better than natural?

Answer 6

Longer half lives.

Better against Enterobacteria (e.coli)

Question 7

Structurally modified penicillins: for antipseudomonas are?

Answer 7

Ureidopenicillins.

Eg. Piperacillin & ticacillin

Question 8

3 types of penicillins

Answer 8

Natural
Structurally modified
Other beta lactam antibiotics

Question 9

Ureidopenicillins (Piperacillin) has better activity against what?

Answer 9

Pseudomonas

Question 10

Pencillin is good for pseudomonas?

Answer 10

No.
Structurally modified are better.
Ureidopenicillins - Piperacillin

Question 11

Piperacillin can be given orally as a tablet to treat the pseudomonas?

Answer 11

False. It is only IV active.

Question 12

Bacteria with cell walls are targeted by different antibiotics because they aren’t all equally active. Why is there the variability?

Answer 12

The betalactam works by working on PBPs (pencillin binding proteins). Different bacteria have different PBPs.

Question 13

S.pyogenes. What antibiotics would you give?

Answer 13

Penicillin V

Amox and ticarcillin can be used but works with the natural beta lactam.

Question 14

Enterococcus. What antibiotics would you give?

Answer 14

Amoxicillin

Not penicillin - weak

Question 15

E.coli. What antibiotic?

Answer 15

It is an Enterobacteria. Therefore natural beta lactams are not great.
Therefore a structurally modified one is needed.
Amoxycillin is indicated.

Question 16

Pseudomonas spp. What antibiotic?

Answer 16

Only Ureidopenicillins
Ticarcillin or Piperacillin
Not penicillin or Amoxycillin

Question 17

What are beta lactamases?

Answer 17

Enzymes that breakdown the beta lactam ring - rending antibiotic useless.

Question 18

Three beta lactamases?

Answer 18

Penicillinases
Cephalosporinases
Extended spectrum beta lactamases.

Question 19

What are the mechanism of resistance to beta lactams?

Answer 19

1 enzymes hydrolyse the beta lactam ring
2 PBPS don’t bind to the beta lactams at all. Like mrsa
3 efflux of antibiotics

Question 20

What Antibiotics can be used for beta lactamases producing bacteria?

Answer 20

Methicillin

Flucloxacillin

Question 21

Flucloxacllin is used for what?

Answer 21

Beta lactamase producing bacteria of S.Aureus
Active against some strephs
Not useful for gram negatives.

Question 22

Flucloxacllin is good for gram positive ?

Answer 22

True

Question 23

Flucloxacllin is good for gram negative ?

Answer 23

False

Question 24

Flucloxacllin's mechanism is what?

Answer 24

Same as beta lactam | But is resistant to the enzymes

Question 25

What can you use to inhibit beta lactamases?

Answer 25

Clavulinic acid | Tazobactam

Question 26

What antibiotics are available by Inhibiting beta lactamase?

Answer 26

Co-amoxyclav (augementin) Timentin - ticarcillin + Clavulinic acid Tazocin: Piperacillin + tazobactam

Question 27

What sort of antibiotic is augmentin

Answer 27

Amoxicillin and Clavulinic acid

Question 28

What can augmentin work against

Answer 28

Staphs Strephs Enterobacteria Anaerobes

Question 29

What do augmentin NOT work against

Answer 29

Mrsa Some enterococci Pseudomonas

Question 30

Side effects of augmentin are?

Answer 30

GI upset | Cholestatic jaundice

Question 31

Difference between the penicillin and cephalosporin

Answer 31

They have a beta lactam ring | But the side chain is different

Question 32

What are first generation cephalosporins.

Answer 32

Cefalexin, cefadroxil For Gram +ve Oral

Question 33

Describe Second generation of cephalosporins?

Answer 33

Cefuroxime | IV and oral

Question 34

Describe 3rd generation cephalosporin.

Answer 34

Ceftriaxone | IV only

Question 35

Describe 4th generation cephalosporin.

Answer 35

Cefepime IV only Gram negative

Question 36

As you go from 1st to 4th gen cephalosporins what changes? ( bioavailability&bacteria type )

Answer 36

``` 1st gen (oral) 4th (IV only) 1st (+ve) 4th (-ve) ```

Question 37

Cephalexin is good for what bacteria types?

Answer 37

Staphs Streps Coliforms

Question 38

What antibiotic would be good for UTI?

Answer 38

1st gen cephalosporin | Cephalexin

Question 39

What can be used for mild resp and skin infections

Answer 39

1st gen cephalosporins | Cephalexin

Question 40

2nd gen cephalosporin and some third gen are useful against what bacteria?

Answer 40

Staphs Streps Coliforms

Question 41

What can be used for pneumonia? (Cephalosporin)

Answer 41

Cefuroxime or ceftriaxone

Question 42

What can be used for cellulitis?

Answer 42

Cefuroxime and ceftriaxone

Question 43

Meningitis can be fought using what type of antibiotic?

Answer 43

Cephalosporins 2/3gen Cefuroxime and ceftriaxone

Question 44

3rd gen cephalosporin - ceftazidime are poor against what bacteria?

Answer 44

Staphs | Streps

Question 45

3rd gen cephalosporin - ceftazidime are good for what bacteria

Answer 45

Coliforms | Pseudomonas

Question 46

Give a specific use of ceftazidime

Answer 46

Hospital acquired pneumonia

Question 47

What is the difference between ceftriaxone and ceftazidime

Answer 47

Ceftriaxone is good against stapes, streps, and Coliforms, Ceftriaxone is poor against pseudomonas Ceftazidime is poor against staphs, streps Ceftazidime is good for Coliforms and pseudomonas Use of ceftriaxone is similar to second gen Ceftazidime is useful against HAP

Question 48

Like penicillinases, there are Cephalosporinases. What bacteria makes this?

Answer 48

Enterobacteria

Question 49

S.aureus is responsible for what resistant mechanism?

Answer 49

Penicillinase

Question 50

S.aureus is responsible for cephalosporinases? True or false.

Answer 50

False | Enterobacteria are

Question 51

What is available against the cephalosporinases in terms of inhibitors?

Answer 51

Nothing

Question 52

What are ESBL

Answer 52

Extended spectrum beta lactamases

Question 53

Describe ESBL

Answer 53

Hydrolyse all beta lactam ring drugs EXCEPT Carbapenems Resistant to other antibiotics

Question 54

What are imipenem and meropenem?

Answer 54

Carbapenems

Question 55

What are the activity of Carbapenems use?

Answer 55

Gram +ve Gram +ve anaerobes

Question 56

How are beta lactam drugs excreted

Answer 56

Renally

Question 57

What effect does beta lactams have on the neuro system

Answer 57

Neurotoxic

Question 58

Side effects associated with beta lactams are?

Answer 58

Neurotoxic Neutropenia Thrombocytopenia Interstitial nephritis

Question 59

The most suitable penicillin for s.pyogenes is?

Answer 59

Penicillin V

Question 60

Most suitable penicillin for S.Aureus is

Answer 60

Flucloxacllin

Question 61

Which beta lactam would be suitable for simple UTI

Answer 61

Cephalosporins 1st gen Cephalexin

Question 62

Which beta lactam would be suitable for a suspected pseudomonas infection?

Answer 62

Ureidopenicillins - ticarcillin or Piperacillin | 3rd gen cephalosporin - ceftazidime

Question 63

When would you consider giving Cefuroxime to a patient who is penicillin allergic?

Answer 63

Cefuroxime is a second gen cephalosporin | So can be used for pneumonia, cellutitis, meningitis

Question 64

Vancomycin and teicoplanin are antibiotics of what class?

Answer 64

Glycopeptides

Question 65

How do vancomycin work (glycopeptides)

Answer 65

Inhibit PGN synthesis

Question 66

What is different about glycopeptides and beta lactam antibiotics? And why is this useful?

Answer 66

Glycopeptides have no beta lactam ring Therefore useful for beta lcatam resistant infections GRAM POSITIVES ONLY

Question 67

Glycopeptides work on what bacteria?

Answer 67

Gram positive only Mrsa Ampicillin resistant enterococci Penicillin resistant pneumococci

Question 68

Why do glycopeptides not work on gram negatives ?

Answer 68

Big molecules | Cannot penetrate membrane

Question 69

What effect do glycopeptides have given that they are big molecules

Answer 69

Can't work on gram negatives Poor tissue penetration Conc:MIC ratio is low Not as effective as beta lactams

Question 70

What is conc:MIC ratio

Answer 70

?

Question 71

Describe the glycopeptide pharmokinetics

Answer 71

No GI uptake Renal excretion Nephrotoxic