CLASSES OF ABX: GLYCOPEPTIDES Flashcards
Glycopeptides examples
Dalbavancin
Teicoplanin
Telavancin
Vancomycin
What spectrum?
Narrow spectrum
Bactericidal
MOA
- 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.
What bacteria do glycopeptides have activity against?
Gram + (anaerobic + aerobic)
MRSA
Vancomycin indications
C.diff
MRSA
Given parenterally for serious infections
Vancomycin - therapeutic index
Narrow
Monitor Cp
Monitor after 3 or 4 doses AND after a dose change
Loading doses may be required due to long half-life
Trough level
10-15 mg/ml
15-20 mg/ml for:
- Endocarditis
- less sensitive MRSA strains
- Complicated S.aureus infections
Indications
- Clostridium difficile infection
- Endocarditis
- Surgical prophylaxis (when high risk of MRSA).
Side effects
- NEPHRO/OTO TOXICITY
- Red-man syndrome
- SJS
- Blood dyscrasias
- Thrombophlebitis
- Risk of anaphylactoid reactions at site of infusion
Nephrotoxicity
Renally excreted
Measure renal function
Signs:
- Low urine output/CrCl
- High serum creatinine/urea
Interactions - nephrotoxicity
Ciclosporin
Ototoxicity
Measure auditory function in elderly.
Avoid if history of deafness
Count patient to report:
- Tinnitus (DISCONTINUE)
- Hearing loss
- Vertigo
What blood disorders can you get as a side effect from glycopeptides?
agranulocytosis, eosinophilia, neutropenia
How to avoid anaphylactic reaction at site of infusion
o avoid rapid infusion
o rotate site
Red-man syndrome
Upper body flushing caused by rapid infusion
Can be associated with hypotension + bronchospasms
Skin disorders
Itching
Rash
SJS
Toxic epidermal necrolysis
Thrombophlebitis
Pain + inflammation of veins at infusion site
Contraindications and cautions
Pregnancy
Avoid vancomycin if there is history of deafness and in the elderly
Pregnancy
Should be avoided in pregnancy unless benefit outweighs risk
Avoid vancomycin unless essential
Must monitor Cp
Breastfeeding
present in milk, significant absorption unlikely
Dose
- Initial doses based on body-weight
- then dose adjustments based on serum-vancomycin concentrations
Trough concentration
15-20 mg/litre
What is the route of administration for vancomycin for systemic infections?
- Vancomycin should only be given parenterally for systemic infections
Why should vancomycin not be given orally for systemic infections
Reduced absorption orally
It is broken down in the stomach before it can have action
Monitoring
FBC
Hepatic + renal function
Urinalysis
Cp
Auditory function in elderly
Vancomycin + suxamethonium
Enhances effect of suxamethonium
