Macrolides

Question 1

MoA

Answer 1

Inhibits bacterial protein synthesis by binding to the 50S subunit of the ribosome.
Broad spectrum
Bacteriostatic

Question 2

Uses

Answer 2

H.pylori
RTIs
Skin and soft tissue infection

Question 3

Examples

Answer 3

• Clarithromycin
• Erythromycin
• Azithromycin
• Telithromycin
• Spiramycin

Question 4

Clarithromycin

Answer 4

BD
Taste disturbance

Question 5

Erythromycin

Answer 5

BD or QDS
Empty stomach (1 hour before or 2 hours after)
Before indigestion remedies - 2 hour gap

Question 6

Telithromycin

Answer 6

Beta-lactam resistant infections
Visual disturbances
Hepatotoxicity
Transient loss of consciousness - DRIVING!!

Question 7

Spiramycin

Answer 7

Toxoplasmosis

Question 8

Side effects

Answer 8

GI effects
QT prolongation
Hepatotoxicity
Ototoxicity at high doses

Question 9

QT interval prolongation

Answer 9

Risk factors:
- Bradycardia
- Heart disease
- Hypokalaemia (K) + Hypomagnesaemia (Mg)
- Concomitant QT prolongation drugs (SSRI, quinine, antipsychotics, amiodarone)

Question 10

GI effects

Answer 10

Most with erythromycin
N + V
Abdominal discomfort
Diarrhoea

Question 11

How to take

Answer 11

With or after food - doesn’t matter EXCEPT for erythromycin

Question 12

Interactions

Answer 12

Erythromycin + Clarithromycin are POTENT enzyme inhibitors.
Warfarin = increased risk of bleeding
Statins = increased risk of myopathy
Theophylline = theophylline toxicity