Antibiotics - II

Question 1

3 key antibiotics that inhibit protein synthesis:

Answer 1

Erthyromycin
Doxycylin
Gentamicin

Question 2

How do antibiotics inhibit protein synthesis?

Answer 2

But attaching to bacterial ribosomes

Question 3

Is antibiotics inhibiting protein synthesis bactericidal or bacteriostactic?

Answer 3

Usually bacteriostatic meaning protein synthesis can resume when antibiotic is removed

Exception: aminoglycosides - binding to ribosome is lethal

Question 4

Delete

Answer 4

Aminoglycosides
Tetracyclines
Macrolides

Question 5

Feature of gentamicin (4):

Answer 5

Most common aminoglycosides

Administered by IV

Bactericidal

Excreted in urine

Question 6

Toxicity of gentamicin:

Answer 6

Causes damage to kidneys and 8th cranial nerve.
Blood levels of aminoglycosides have to be monitored.

Question 7

Tetracyclines (4):

Answer 7

E.g Doxycylin

Bacteriostatic

Prevents attachment of tRNA

Useful against intracellular bacteria

Question 8

Side effects of tetracyclines:

Answer 8

Destruction of normal intestinal flora
Staining of bone/teeth in children under 12

Question 9

Macrolides:

Answer 9

E.g. Erythromicin

Bacteriostatic

Lipophilic - Useful against intracellular bacteria

Excreted via liver

Safe in pregnancy

Question 10

Quinolones

Answer 10

E.g. Ciproflaxin

Bactericidal

Broad spectrum

Targets DNA - Causes damage by introducing breaks in the DNA

Question 11

Nitroimadazoles:

Answer 11

E.g. Mentronidazole - oral and IV

Works against Protozoa

Activated by reduction

Damages DNA

Question 12

What is the folic acid?

Answer 12

Vitamin required for synthesis of key cellular components

Question 13

Role of trimethoprim:

Answer 13

Can inhibit folic acid synthesis

Question 14

Function of prescribing antibiotics in combination:

Answer 14

Covers broad range of infecting organisms, preventing resistance.

Never combine bacteriostatic and bactericidal.

Question 15

Side effect of ciproflaxin:

Answer 15

Tendinitis

Question 16

Side effect of metronidazole:

Answer 16

Interacts with alcohol

Question 17

High risk antibiotics:

Answer 17

4 C’s increase risk of “C Diff” infection:
- Cephalosporins
- Co-amoxiclav
- Ciprofloxacin
- Clindamycin

Question 18

Empirical prescribing:

Answer 18

Prescribing without lab identification, based on likely pathogen

Question 19

Targeted prescribing:

Answer 19

With lab identification