INFECTION: VANCOMYCIN

Question 1

VANCOMYCIN; INDICATIONS

Answer 1

• Treatment of Gram-positive infection, e.g. endocarditis, where infection is severe and/or penicillins cannot be used due to resistance (e.g. meticillin-resistant
• Staphylococcus aureus [MRSA]) or allergy. Treatment of antibiotic-associated colitis caused by Clostridium difficile infection (usually second-line where metronidazole is ineffective or poorly tolerated).

Question 2

VANCOMYCIN; MOA

Answer 2

• Vancomycin inhibits growth and cross-linking of peptidoglycan chains, inhibiting synthesis of the cell wall of Gram-positive bacteria
• It therefore has specific activity against Gram-positive aerobic and anaerobic bacteria and is inactive against most Gram-negative bacteria, which have a different (lipopolysaccharide) cell wall structure.

Question 3

VANCOMYCIN: ADVERSE EFFECTS

Answer 3

The most common adverse effect is pain and inflammation of the vein (thrombophlebitis) at the infusion site

• If vancomycin is infused rapidly, severe adverse reactions can occur - anaphylactoid reactions classically described as ‘red man syndrome’. This is characterised by generalised erythema and may be associated with hypotension and bronchospasm.
• Anaphylactoid reactions are not antigen-mediated (i.e. not true allergy), but are due to non-specific degranulation of mast cells
• True rxns vancomycin (immediate or delayed hypersensitivity) can also occur
• Intravenous vancomycin can cause nephrotoxicity, including renal failure and interstitial nephritis, ototoxicity, with tinnitus and hearing loss, and blood disorders, including neutropenia and thrombocytopenia.

Question 4

VANCOMYCIN; WARNINGS

Answer 4

• Vancomycin treatment requires careful monitoring of plasma drug concentrations and dose adjustment to avoid toxicity
• Particular caution including dose reduction should be taken when prescribing for people with renal impairment and the elderly (increased risk of hearing impairment)

Question 5

VANCOMYCIN; INTERACTIONS

Answer 5

Vancomycin increases the risk of ototoxicity and/or nephrotoxicity when prescribed with aminoglycosides, loop diuretics or ciclosporin (an immunosuppressant drug).