Antimicrobial Therapy

Question 1

Sometimes use antimicrobials as?

Answer 1

Prophylaxis

Question 2

Antimicrobial is

Answer 2

Something used to treat infection

Question 3

Treating infections more than drugs

Answer 3

Perform surgery/ drainage: remove dead tissue and pus

Give an antimicrobial

Question 4

Inappropriate prescribing

Can lead to

Answer 4

Risk of increasing antimicrobial resistance

Side effects (c.difficile)

IV administrations instead of oral increase risk of infected IV

Question 5

Before starting treatment

Answer 5

What is site and likely cause of infection

Is an antimicrobial necessary at all

Is there evidence of infection that will respond

Don’t use antimicrobials as antipyretics

Check allergy history

Question 6

Antibiotics can be essential to

Answer 6

Limit tissue spread and collateral damage

Treat high morality infections and save lives

Shorten durations of pain and suffering

Reduce sequels of uncontrolled infection such as cerebral damage after meningitis

Question 7

Common over prescribing problems

Answer 7

Too long of a colourise given (indication and stop date is on drug chart)

Too much given IV

Too broad spectrum -select narrow spectrum agents

Misuse of prophylaxis

Question 8

Antimicrobial ssuspectibilty test

Answer 8

Disc testing

MIC and MBC

Question 9

MIC and MBC

Answer 9

Minimum inhibitory concentration
A- lowest concentration of the antibiotic being tested that inhibits growth of the organism in a broth

Minimum bactericides concentration

Lowest concentration that kills organisms

Important for endocarditis and other critical infections

Question 10

Beta lactams are

Answer 10

Penicillins, cephalosporins and carbapenems

Question 11

What do beta lactams have in common

Answer 11

They work on the cell wall

Question 12

Beta lactams act on the cell wall by

Answer 12

Binding to the penicillin binding proteins in bacteria cell membranes, these proteins help synthesise peptidoglycan in the cell wall

Question 13

In gram negative bacteria the beta lactams

Answer 13

Must also penetrate the outer membrane

Question 14

Penicillin alternatives

Answer 14

Vancomycin
Teicoplanin

(Glycopeptides)

Question 15

Glycopeptides work on

Answer 15

Gram positive bacteria only

Question 16

Examples of macrolides

Answer 16

Erythromycin, clarithromycin,

Azithromycin

Question 17

Macrolides used when

Answer 17

Used in penicillin-allergic patients against staphylococci, streptococci eg skin or throat infections. Also for atypical pneumonia.

Question 18

Macrolides work on

Answer 18

Bacterial ribosomes

Question 19

Erythromycin

Answer 19

Interferes with protein synthesis by ribosomal binding

Question 20

Azithromycin/clarithromycin

Answer 20

Newer type of macrolides with longer half lives and fewer side effects

Question 21

Tetracyclines do what

Answer 21

Inhibit binding of transfer RNA to the ribosome

Question 22

Tetracycline used when

Answer 22

for respiratory tract and soft tissue infections

Question 23

Example of tetracycline

Answer 23

Oxytetracycline and doxycycline

Question 24

Aminoglycosides do what

Answer 24

Interfere with ribosomal reading of mRNA

Work on gram negative bacteria

Question 25

Aminoglycosides used predominantly when

Answer 25

Serious sepsis

Question 26

Example of an aminoglycoside

Answer 26

Gentamicin

Question 27

Antibiotics working against ribosomes

Answer 27

Aminoglycosidsesmacrolides

Tetracyclines

Question 28

Quinolone do what

Answer 28

Inhibit DNA synthase

Question 29

Quinolone send I

Answer 29

Floxacin

Question 30

Trimethoprim and co trimoxazole and co trimoxazole

Answer 30

Work on gram negative and gram positive

Stop synthesis of bacterial dna