Glycopeptides (high risk)

Question 1

what is the common indications for Vancomycin?

Answer 1

1) Treatment of G+VE infection, e.g. endocarditis, where infection is severe and/or penicillins cannot be used due to resistance (MRSA) or allergy.
2) Antibiotic-associated colitis caused by C.diff ( 2nd line where metronidazole is ineffective or poorly tolerated).

Question 2

outline the Spectrum of activity of vancomycin

Answer 2

1) Relatively narrow spectrum of activity against G+ve, notably Staphylococcus spp. (including MRSA)
2) It has no activity against Gram-negative organisms.
3) Streptococcus spp. and C. difficile. VRE are of increasing concern.

Question 3

Outline the MoA of vancomycin

Answer 3

1) Inhibits growth and cross-linking of peptidoglycan chains, inhibiting synthesis of the cell wall of Gram-positive bacteria, thus lysing and killing the bacteria (bactericidal).

Question 4

outline the Important adverse effects with regards to vancomycin and teicoplanin

Answer 4

1) pain and thrombophlebitis at the infusion site
2) If infused rapidly red man syndrome can occur. (generalised erythema, hypotension and bronchospasm)
3) Can cause nephrotoxicity, including renal failure and interstitial nephritis
4) Ototoxicity, with tinnitus and hearing loss
5) Neutropenia and thrombocytopenia

Question 5

who should vancomycin be used in caution with?

Answer 5

1) requires careful monitoring of plasma drug concentrations and dose adjustment to avoid toxicity.
2) Caution and dose reduction in renal impairment and the elderly (increased risk of hearing impairment)
3) Pregnant, breastfeeding

Question 6

is vancomycin or teicoplanin associated with a higher incidence of nephrotoxicity?

Answer 6

Vancomycin is associated with a higher incidence

Question 7

list some of the important interactions with regards to vancomycin

Answer 7

increased risk of ototoxicity and/or nephrotoxicity when prescribed with aminoglycosides, loop diuretics or ciclosporin

Question 8

What is the therapeutic range for vancomycin?

Answer 8

1) initial doses based on body-weight; subsequent dose based on serum-vancomycin concentrations . Long half life, loading dose may be required
2) pre-dose (‘trough’) 10-20 mg/litre. Therapeutic range 15–20 mg/litre is usually recommended

Question 9

What patient parameters should be monitored in those taking vancomycin?

Answer 9

1) FBC
2) Hepatic & renal function
3) Urinalysis
4) Plasma levels (15–20 mg/litre)
5) Hearing

Question 10

list 2 glycopeptides

Answer 10

vancomycin, teicoplanin