23. Intro to antibiotics

Question 1

Which penicillin or cephalosporins has anti-pseudomonal activity?

Answer 1

Piperacillin-Tazobactam

Question 2

What percentage of people have a history of penicillin allergy?

Answer 2

5%

Question 3

Which penicillin is most suitable to treat a beta-lactamase producing E. coli urinary tract infection?

Answer 3

Co-amoxiclav

Question 4

Which organism is always resistant to macrolides?

Answer 4

Pseudomonas augerosa

Question 5

What are the functions of antibiotics?

Answer 5

Prophylaxis: medical or surgical
Treatment: empiric or targeted

Question 6

What ways can antibiotics be classified?

Answer 6

Antibiotic family
Mechanism of action
Spectrum
Antimicrobial activity (bacteriostatic or bactericidal)

Question 7

What is important for how effective bacteriostatic treatment is?

Answer 7

The host’s immune response

Question 8

What specific infection is bacteriostatic antibiotics especially useful in?

Answer 8

Group A strep to prevent toxin production

Question 9

What are bactericidal antibiotics especially useful in?

Answer 9

Immunosuppressed patients

Severe infections: BSI, meningitis, endocarditis

Question 10

What are the methods of susceptibility testing?

Answer 10

Disk diffusion
MIC
Genotypic methods

Question 11

What is the disadvantage in genotypic methods as a way of finding antibiotic susceptibility?

Answer 11

The gene might be present but not switched on

Question 12

What is the general mechanism of action of beta lactams?

Answer 12

Inhibit cell wall synthesis

Question 13

Name 4 penicillins

Answer 13

Benzylpenicillin
Ampicillin/amoxicillin
Flucloxacillin

Question 14

What organisms does benzylpenicillin target?

Answer 14

Gram positive cocci (narrow spectrum)

Strep, staph and neisseria

Question 15

What infections does benzylpenicillin treat?

Answer 15

Meningitis
Endocarditis
Cellulitis

Question 16

Which penicillins are broad spectrum?

Answer 16

Ampicillin

Amoxicillin

Question 17

What infections do ampicillin and amoxicillin treat?

Answer 17

UTIs

RTIs

Question 18

What bacteria is flucloxacillin used for?

Answer 18

MSSA

Question 19

Should cephalosporins be given to a patient with a penicillin allergy?

Answer 19

Can be given to a patient with a mild penicillin allergy

Question 20

Name the classes of beta lactams

Answer 20

Penicillins
Cephalosporins
Carbapenems
Monobactams

Question 21

Name a first generation cephalosporin

Answer 21

Cefaclor

Question 22

What is cefaclor used to treat?

Answer 22

RTIs and UTIs cause by gram +

Question 23

Name a second generation cephalosporin

Answer 23

Cefuroxime

Question 24

What is cefuroxime used to treat?

Answer 24

RTIs

Given as surgical prophylaxis

Question 25

Name a third generation cephalosporin

Answer 25

Ceftriaxone

Question 26

What is ceftriaxone used to treat?

Answer 26

Meningitis

Question 27

What is synergy?

Answer 27

Effect of two drugs in combination is greater than alone

Question 28

Are carbapenems narrow or broad spectrum?

Answer 28

Very broad

Question 29

What resistant organisms are carbapenems active against?

Answer 29

EBSL producers

Question 30

Name 2 carbapenems

Answer 30

Meropenem | Ertapenem

Question 31

What organisms are monobactams active against?

Answer 31

Gram -

Question 32

Name a monobactam

Answer 32

Aztreonam

Question 33

What is the mechanism of action of glycopeptides?

Answer 33

Inhibit cell wall synthesis of gram +

Question 34

What organisms are glycopeptides especially useful in treating?

Answer 34

MRSA | C. difficile

Question 35

Name 2 glycopeptides

Answer 35

Vancomycin | Teicoplanin

Question 36

What bacteria are aminoglycosides active against?

Answer 36

Gram - bacilli, staph aureus, mycobacteria, brucella, e.coli, pseudomonas Inactive against anaerobes

Question 37

What infections are aminoglycosides used to treat?

Answer 37

Intra-abdominal | Infective endocarditis

Question 38

What are the possible toxic effects of aminoglycosides?

Answer 38

Nephrotoxicity | Ototoxicity

Question 39

Name an aminoglycoside

Answer 39

Gentamicin | Streptomycin for TB

Question 40

What is the mechanism of action of aminoglycosides?

Answer 40

Inhibit protein synthesis

Question 41

Name 3 macrolides

Answer 41

Clarithromycin Erythromycin Azithromycin

Question 42

What infections are treated with macrolides?

Answer 42

Atypical pneumonias: mycoplasma, coxiella, chlamydia, legionella

Question 43

What is the mechanism of action of macrolides?

Answer 43

Inhibit protein synthesis

Question 44

Are quinolones bacteriostatic or bactericidal?

Answer 44

Bactericidal: inhibit DNA gyrase

Question 45

Name 2 quinolones

Answer 45

Ciproflaxin | Levofloxacin

Question 46

What infections are treated with quinolones?

Answer 46

UTIs Intra-abdominal Caused by gram - bacilli

Question 47

Why are quinolones not often used?

Answer 47

Side effects include cartilage toxicity and tendon rupture

Question 48

Name a tetracycline

Answer 48

Doxycycline

Question 49

What bacteria are susceptible to tetracyclines?

Answer 49

Chlamydia Rickettsia Coxiella Mycoplasma

Question 50

Why are tetracyclines contraindicated in pregnant women and children?

Answer 50

Stain growing teeth

Question 51

What is the general mechanism of action of tetracyclines?

Answer 51

Inhibit protein synthesis

Question 52

What types of microbes is metronidazole used to treat?

Answer 52

Anaerobic and protozoa

Question 53

What are the uses of metronidazole?

Answer 53

Prophylaxis in bowel surgery | Treat intra-abdominal infections

Question 54

What class of antibiotics are usually combined with metronidazole?

Answer 54

Cephalosporins

Question 55

What are the factors in choosing an antibiotic?

Answer 55

``` Site of infection Community or HCAI Local resistance Previous antibiotics Previous lab results Allergy ```

Question 56

What are the options for updating antibiotic treatment at 24-48 hours?

Answer 56

``` Stop antibiotic IV to oral Change (more narrow or broad) Continue Outpatient Parenteral Antibiotic Therapy ```

Question 57

What is antibiotic stewardship?

Answer 57

Programmes and interventions to improve the use of antibiotics