Antibiotic Therapy

Question 1

Antibiotic definition:

Answer 1

A drug used to treat or prevent infection caused by microorganisms

Question 2

Bacteriostatic definition:

Answer 2

Inhibits growth of bacteria

Question 3

Bactericidal definition:

Answer 3

Kills bacteria

Question 4

How do antibiotics act on bacterial cell walls?

Answer 4

Inhibit cell wall synthesis by preventing cross linking of peptidoglycan
Bactericidal process

Question 5

What type of antibiotic is Penecillin?

Answer 5

β lactam

Question 6

Broad spectrum definition:

Answer 6

Can kill a with range of bacteria

Question 7

Examples of penicillins (3):

Answer 7

Fluclolaxacillin
Amoxicillin
Co-amoxiclav

Question 8

Features and of gylcopeptides (4):

Answer 8

Inhibits cell wall synthesis through different mechanisms

Bactericidal

Excreted via kidneys and urine

NO activity agaisnt Gram -ve organisms

Question 9

Example of glycopeptide:

Answer 9

Vancomycin (IV)
Teicoplanin (IV)

Question 10

How do antibiotics inhibit protein synthesis?

Answer 10

By attaching to bacterial ribosomes

Protein synthesis can resume when antibiotic in removed (bacteriostatic) apart from in aminoglycosides where binding to ribosome kills bacteria

Question 11

Lipophilic definition:

Answer 11

Easily pass through cell membranes

Useful for infections where bacteria ‘hide’ in host cells

Question 12

General side effects of antibiotics (5):

Answer 12

nausea
vomiting
diarrhoea
rashes
Candida infection

Question 13

Penicillin side effects:

Answer 13

General: Hypersensitivity/skin reactions

Flucloxacillin and co-amoxiclav: cholestatic jaundice

Question 14

Penicillin pros (3):

Answer 14

Safe in pregnancy
Few side effects
Range from narrow to broad spectrum

Question 15

Penicillin cons:

Answer 15

Allergic to 1 penicillin = allergic to all penicillin
Excreted rapidly via kidneys can cause resistance

Question 16

What are the target of ß-lactams?

Answer 16

Penicillin binding proteins (PBPs)

Question 17

Common prescribed cell wall anti microbes (3)

Answer 17

• Penicilins
• Cephalosporins
• Glycopeptides

Question 18

3 Principle penicillin compounds:

Answer 18

• Benzylpenicillin
• Phenoxymethyl penicillin
• Benzathine penicillin

Question 19

Amoxicillin:

Answer 19

well tolerated antibiotic

Well absorbed when given orally

Low binding to plasma proteins

good tissue distribution

beta lactamases can make it less effective

Question 20

Co-amoxiclav

Answer 20

Amoxicillin + clavulanic acid

Clauvanic acid: beta-lactamase inhibitor, microbial enzyme, NO antibiotic properties of its own

Question 21

Flucloxacillin

Answer 21

IV and oral

Narrow spectrum antibiotic

Commonly prescribed for Straph and Strep

Question 22

Temocillin

Answer 22

IV

gram-negative spectrum

beta-lactamase resistant penicillin

Used for coliforms

Active against ESBL producing organisms

Question 23

Cephalosporin examples

Answer 23

Cefaclor
cefadroxil
cefalexin

Question 24

Cephalosporins

Answer 24

bactericidal

Excreted via kidneys and urine

resistant to β-lactamases

Few side affects

safe in pregnancy

Broad-spectrum antibiotics

Question 25

Side effects of glycopeptides :

Answer 25

vancomycin damages kidneys, occasionally causes ‘red man syndrome’ (allergy)