CLASSES OF ABX: GLYCOPEPTIDES

Question 1

Glycopeptides examples

Answer 1

Dalbavancin
Teicoplanin
Telavancin
Vancomycin

Question 2

What spectrum?

Answer 2

Narrow spectrum
Bactericidal

Question 3

MOA

Answer 3

• Glycopeptides bind to precursors of cell wall synthesis
• Leads to interference of the penicillin-binding protein (PBP) enzymes such as transpeptidases
• Cell wall synthesis stops, leading to cell death.

Question 4

What bacteria do glycopeptides have activity against?

Answer 4

Gram + (anaerobic + aerobic)
MRSA

Question 5

Vancomycin indications

Answer 5

C.diff
MRSA
Given parenterally for serious infections

Question 6

Vancomycin - therapeutic index

Answer 6

Narrow
Monitor Cp
Monitor after 3 or 4 doses AND after a dose change
Loading doses may be required due to long half-life

Question 7

Trough level

Answer 7

10-15 mg/ml

15-20 mg/ml for:
- Endocarditis
- less sensitive MRSA strains
- Complicated S.aureus infections

Question 8

Indications

Answer 8

• Clostridium difficile infection
• Endocarditis
• Surgical prophylaxis (when high risk of MRSA).

Question 9

Side effects

Answer 9

• NEPHRO/OTO TOXICITY
• Red-man syndrome
• SJS
• Blood dyscrasias
• Thrombophlebitis
• Risk of anaphylactoid reactions at site of infusion

Question 10

Nephrotoxicity

Answer 10

Renally excreted
Measure renal function
Signs:
- Low urine output/CrCl
- High serum creatinine/urea

Question 11

Interactions - nephrotoxicity

Answer 11

Ciclosporin

Question 12

Ototoxicity

Answer 12

Measure auditory function in elderly.
Avoid if history of deafness
Count patient to report:
- Tinnitus (DISCONTINUE)
- Hearing loss
- Vertigo

Question 13

What blood disorders can you get as a side effect from glycopeptides?

Answer 13

agranulocytosis, eosinophilia, neutropenia

Question 14

How to avoid anaphylactic reaction at site of infusion

Answer 14

o avoid rapid infusion
o rotate site

Question 15

Red-man syndrome

Answer 15

Upper body flushing caused by rapid infusion
Can be associated with hypotension + bronchospasms

Question 16

Skin disorders

Answer 16

Itching
Rash
SJS
Toxic epidermal necrolysis

Question 17

Thrombophlebitis

Answer 17

Pain + inflammation of veins at infusion site

Question 18

Contraindications and cautions

Answer 18

Pregnancy
Avoid vancomycin if there is history of deafness and in the elderly

Question 19

Pregnancy

Answer 19

Should be avoided in pregnancy unless benefit outweighs risk

Avoid vancomycin unless essential
Must monitor Cp

Question 20

Breastfeeding

Answer 20

present in milk, significant absorption unlikely

Question 21

Dose

Answer 21

• Initial doses based on body-weight
• then dose adjustments based on serum-vancomycin concentrations

Question 22

Trough concentration

Answer 22

15-20 mg/litre

Question 23

What is the route of administration for vancomycin for systemic infections?

Answer 23

• Vancomycin should only be given parenterally for systemic infections

Question 24

Why should vancomycin not be given orally for systemic infections

Answer 24

Reduced absorption orally
It is broken down in the stomach before it can have action

Question 25

Monitoring

Answer 25

FBC
Hepatic + renal function
Urinalysis
Cp
Auditory function in elderly

Question 26

Vancomycin + suxamethonium

Answer 26

Enhances effect of suxamethonium