Anti microbial agents 1 and 2

Question 1

What are the 3 targets of abx?

Answer 1

Cell wall synthesis

Bacterial protein synthesis

DNA gyrase and other prokaryote specific enzymes

Question 2

Which abx target cell wall synthesis (peptidoglycan layer)

Answer 2

B lactam

Glycopeptides

Question 3

What subtypes of beta lactams are there?

Answer 3

Penicillin
Cephalosporin
Carbapenems

Question 4

What subtypes of glycopeptides are there?

Answer 4

Vancomycin and teicoplanin

Question 5

What are beta lactams method of action?

Answer 5

Effective against rapidly dividing bacteria

Effective against bacteria that have peptiodoglycan cell walls

Bactiricidal

Question 6

What are some examples of bacteria that do not have a peptidoglycan cell wall?

Answer 6

Mycoplasma and chlamydia

Question 7

Which beta lactam can be used against gram positive like strep and clostridia?

Answer 7

Penicillin

Question 8

What is amoxicillin?

Answer 8

Broad spectrum penicillin that extends cover to enterococci and gram negative organisms

Question 9

Which abx are stable to beta lactamase produced by bacteria?

Answer 9

Flucloxacillin (Penicillin-like)

Penicillins and amoxacillin are broken down by beta lactamase

Question 10

What beta lactam covers Pseudomonas and other gram negative organisms?

Answer 10

Piperacillin

But is broken down by beta lactamase

Question 11

What are some beta lactamase inhibitors

Answer 11

Clavulanic acid

Tazobactam

Question 12

What is co amoxiclav

Answer 12

Amoxicillin and clavulanic acid

Question 13

Are cephalosporins stable to beta lactamases?

Answer 13

Yes

Question 14

What are some first gen cephalosporins

Answer 14

Cephalexin

Question 15

What are some second gen cephalosporins

Answer 15

Cefuroxime

Question 16

Cefuroxime vs co amoxiclav, whats the difference?

Answer 16

Both are resistant to beta lactamasesm but cefuroxime is less active against anaerobes and need to add metronidazole

Question 17

What can the 3rd gen cephalosporin ceftriaxone be used for?

Answer 17

Sepsis

Meningococcal

Pneuomococcal

But gives rise to C.difficile

Question 18

What can the 3rd gen cephalosporin ceftazidime be used for?

Answer 18

Pseudomonas

Question 19

What organisms are resistant to all cephalosporins

Answer 19

ESBL producing organisms

Question 20

Which type of Beta lactams are resistant to ESBL?

Answer 20

Carbapenems

Question 21

What are some examples of Carbapenems

Answer 21

Meropenem
Imipenem
Ertapenem

Question 22

How are beta lactams excreted

Answer 22

Renally

Question 23

Will beta lactams cross the BBB?

Answer 23

No, but can be used in meningitis

Question 24

Are beta lactams cross reactive

Answer 24

Penicillins have about 10 % cross reactivity with cephalosporins and carbapenems

Question 25

What are glycopeptides effective against?

Answer 25

Gram positive ONLY as they weaken the peptidoglycan cell wall

Question 26

Which infections are glycopeptides primarily used for?

Answer 26

MRSA (iv only)

Question 27

Which glycopeptides can be used for c difficile

Answer 27

Vancomycin

Question 28

What do you need to note about glycopeptides?

Answer 28

Nephrotoxic

Question 29

Which abx inhibit protein synthesis in bacteria?

Answer 29

Amnioglycasides Tetracyclines Macrolides Chloramphenicol Oxazolidinones

Question 30

What organisms are aminogylcasides used against?

Answer 30

Gentamicin and tobramycin are used against Pseudomonas aeruginosa Primarily used against gram negatives

Question 31

What can aminoglycasides and beta lactams be used synergistically for?

Answer 31

Endocarditis

Question 32

What can tetracyclines be used for?

Answer 32

Intracellular pathogens such as chalmydia, legionella, rickettsiae, mycoplasma MRSA Atypical pneumonia Soft tissue infections

Question 33

What to keep in mind for tetracyclines

Answer 33

Not used in preggo women or children Light sensitive rash

Question 34

What can macrolides be used in

Answer 34

Mild stpah or strep infections in those who have penicillin allergy Camplylobacter sp and legionella pneumophilia Atypical pneumonia

Question 35

Name a macrolide used against salmonella

Answer 35

Erythromycin

Question 36

Name some new macrolides

Answer 36

Clarithromycin and azithromycin which have higher half life so can be used in paeds and preggo women

Question 37

When is chloramphenicol used?

Answer 37

Meningococcal and penuomococcal in penicillin allergy people Eye preparations

Question 38

What are the down sided of chloramphenicol

Answer 38

Grey bebe syndrome Aplastic anaemia

Question 39

What can oxazolidinones be used for and give an example of this abx

Answer 39

Gram +ve organisms like MRSA and VRE Linezolid

Question 40

What are some downsides of oxazolidinones?

Answer 40

Can cause thrombocytopaenia and optic neuritis

Question 41

What abx inhibit bacterial DNA synthesis?

Answer 41

Quinolones Nitroimidazoles

Question 42

What can floroquinalones be used against?

Answer 42

Gram -ve organisms Pseudomonas aeruginosa UTI Pneumonia and atypical pneumonia Bacterial gastroenteritis

Question 43

What do you need to watch out for in floroquinalones

Answer 43

Can cause tendonitis and seizures (especially in those using steroids)

Question 44

What can nitroimidazoles be used for?

Answer 44

Exclusively against anaerobes and protozoa

Question 45

Which abx closely related to nitroimidazoles can be used for simple UTIs

Answer 45

Nitrofurans like nitrofurantoin can be used as they are excreted via urine and can be used against e coli and staph and enterococci

Question 46

Which abx inhibit RNA synthesis

Answer 46

Rifamycins such as rifampicin and rifabutin

Question 47

What can rifampicin be used against?

Answer 47

Mycobacteria (TB) and chlamydia

Question 48

What needs to be noted when using rifampicin

Answer 48

Interaction with oral contraceptives and warfarin Monitor LFTs Can turn urine orange

Question 49

Why should rifampicin never be used for short term prophylaxis and what is the exception

Answer 49

Develop resistance really quickly due to chromosomal mutation Can be used for meningococcal infection

Question 50

What can daptomycin be used for

Answer 50

Gram +ve Treat MRSA and VRE infections

Question 51

What can colistin be used for?

Answer 51

Gram -ve - Pseudomonas, acinetobacter and klebsiella Nephrotoxic Not absorbed orally

Question 52

What is cotrimoxazole and what is it sued for?

Answer 52

Sulfonamide and diaminopyrimidine (trimethoprim) Used in HAP, soft tissue infections and pneuomocystic pmeumonia in HIV

Question 53

What are some methods of abx resistance

Answer 53

Inactivation of abx Modification or replacement of target Reduced abx accumulation Bypass abx sensitive step

Question 54

Which organisms have the biggest beta lactamase method of inactivating abx

Answer 54

Staph auereus Gram -ve bacilli

Question 55

What is the method of resistance of penicillin in pneuomococci and MRSA

Answer 55

Altered penicillin binding protein

Question 56

Can penicillin be used for strep penumonia

Answer 56

The resistance is not due to beta lactamase. So co amoxiclov will not be useful Resistance can be overcome by giving high dosage of amoxicillin

Question 57

Why can't macrolides be used against UTIs

Answer 57

Metabolised by liver and not excreted via the bladder

Question 58

What abx would you use for pharyngitis due to Group A Strep

Answer 58

Narrow spectrum penicillin

Question 59

What side effects can aminoglycasides cause?

Answer 59

Ototoxicity

Question 60

What is the minimum inhibitory concentration

Answer 60

The lowest concentration of an antibiotic that prevents the visible growth of bacteria It should be below the breakpoint

Question 61

How would you treat sepsis or hospital acquired pneumonia

Answer 61

Broad spectrum abx

Question 62

What would you use for E coli UTI?

Answer 62

Amoxicillin