Infectious diseases: Pharmacology - Vancomycin

Question 1

Mechanism of action of vancomycin

Answer 1

Binds to D-Ala-D-Ala residue on bacterial cell membrane peptidoglycan, preventing elongation and cross-linking
Causes instability of cell membrane leading to lysis

Question 2

Vancomycin class

Answer 2

Glycopeptide antibiotic

Question 3

Coverage of vancomycin

Answer 3

Active against Gram positives
Large MW prevents it from penetrating cell wall of Gram negatives (with exception of Flavobacterium)

Question 4

Describe the pharmacokinetics of vancomycin

Answer 4

Absorption: poor PO absorption, must be given parenterally (with exception of in C. diff where intestine is intended site of action)
Distribution: widely distributed including CSF
Metabolism: not metabolised
Excretion: renally cleared via glomerular filtration (dose reduction required in renal impairment)

Question 5

Typical indications for vancomycin use

Answer 5

MRSA
C. diff colitis (metronidazole first-line)

Question 6

Four adverse reactions to vancomycin

Answer 6

1. Phlebitis
2. Fever
3. Ototoxicity (rare)
4. Nephrotoxicity