Antimicrobial Chemotherapy

Question 1

MIC

Answer 1

Minimal inhibitory concentration

The minimum concentration of antimicrobial needed to inhibit visible growth of a given organism

Question 2

MBC

Answer 2

Minimal bactericidal concentration

The minimum concentration of the antimicrobial needed to kill a given organism

Question 3

Routes of administration

Answer 3

Topical
Systemic (internally, either orally or parenterally)
Parenteral (IV or IM)

Question 4

Antibiotic modes of action

Answer 4

Inhibition of cell wall synthesis
Inhibition of protein synthesis
Inhibitors of nucleic acid synthesis

Question 5

Beta lactams

Answer 5

Penicillins and cephalosporins

Question 6

Glycopeptides

Answer 6

Vancomycin and teicoplanin

Question 7

Inhibition of cell wall synthesis

Answer 7

Beta lactams

Glycopeptides

Question 8

What type of bacteria do glycopeptides work on? (gram positive or negative)

Answer 8

Gram positive

Question 9

Toxic antibiotics

Answer 9

Vancomycin

Gentamicin

Question 10

Inhibition of protein synthesis

Answer 10

Aminoglycosides
Macrolides and Tetracyclines
Oxazolidinones
Cyclic Lipopeptide

Question 11

Example of an aminoglycoside and what type of bacteria do they work against

Answer 11

Gentamicin
Gram negative bacilli
TOXIC

Question 12

Macrolides

Answer 12

Erythromycin

Clarithromycin

Question 13

Inhibitors of nucleic acid synthesis

Answer 13

Trimethoprim and sulphamethoxazole (combined form => cotrimoxazole)
Fluoroquinolones

Question 14

Fluoroquinolones

Answer 14

Ciprofloxacin (gram negative, not in children)

Question 15

What are MRSA resistant to?

Answer 15

All penicillins and cephalosporins

Question 16

What infection is a side effect of antibiotic therapy?

Answer 16

Clostridium difficile (CDI)

Question 17

How is CDI treated?

Answer 17

Oral metronidazole or oral vancomycin

Question 18

Antifungal drug classes

Answer 18

Polyenes
Azoles
Allylamines
Echinocandins

Question 19

Polyenes

Answer 19

Amphotericin B

Nystatin

Question 20

Amphotericin B

Answer 20

Polyene
IV
Toxic

Question 21

Fluconazole

Answer 21

Used to treat yeast, not all yeasts are sensitive

Question 22

What is used to treat aspergillosis?

Answer 22

Voriconazole and itraconazole

Question 23

Terbinafine

Answer 23

Allylamine

Treatment of fungal infections of skin and nails

Question 24

What are echinocandins used to treat?

Answer 24

Serious candida and aspergillus infections

Question 25

What does aciclovir treat?

Answer 25

Herpes simplex and varicella zoster

Question 26

Penicillins

Answer 26

Penicillin V Amoxicillin Flucloxacillin Co-amoxiclav

Question 27

In what way is trimethoprim toxic?

Answer 27

Folate inhibitor

Question 28

What is linezolid used for?

Answer 28

2nd line agent for MSSA, MRSA, VRE

Question 29

VRE

Answer 29

Vancomycin-resistant enterococci

Question 30

What is empiric therapy?

Answer 30

Without microbiology results

Question 31

What is directed therapy?

Answer 31

Based on microbiology results

Question 32

Principles of prescribing

Answer 32

Indications for antimicrobials Diagnosis Patient characteristics Antimicrobial selection

Question 33

Types of antibacterial sensitivity testing

Answer 33

``` Disk defusion (to test for resistance) Etest (for MIC) ```

Question 34

What are the four main mechanisms of resistance?

Answer 34

Enzymatic inactivation of drug Modified targets for drugs Reduced permeability to drug Efflux of drug

Question 35

Genetics of resistance

Answer 35

Chromosomally mediated | Plasmid mediated

Question 36

How are plasmids passed between bacteria?

Answer 36

Conjugation

Question 37

Medically important resistant organisms

Answer 37

``` MRSA VRE ESBL CPE C diff ```

Question 38

ESBL

Answer 38

Extended spectrum beta lactamase

Question 39

CPE

Answer 39

Carbapenemase producing enterobacteriaceae

Question 40

Reasons for failure of therapy

Answer 40

Inadequate dose of antibiotic Inappropriate route Non-compliance with antibiotic Bacteria walled off in abscess cavity Foreign bodies eg surgical implants/prosthesis Poor penetration of drug to site of infection

Question 41

Antibiotics with good biofilm activity

Answer 41

Rifampicin Daptomycin Ceftobiprole

Question 42

How can healthcare workers help to tackle AMR?

Answer 42

Practicing effective infection prevention & control Prescribing and dispensing antibiotics only when truly needed Prescribing & dispensing the right antibiotic(s) for the right duration to treat the illness