Vancomycin is a glycopeptide antibiotic which is active against methicillin resistant Staphylococcus aureus (MRSA).¹ It has been designated as a high-risk (high-alert) medication by the World Health Organization (WHO).² Due to its narrow therapeutic index and toxicity profile, which includes nephrotoxicity (kidney damage) and ototoxicity (hearing loss), vancomycin requires therapeutic drug monitoring (TDM) i.e. blood level measurement to ensure safe and effective dosing.

Vancomycin incidents

The Clinical Risk Unit noted the occurrence of incidents, reported on NIMS, relating to vancomycin, which prompted a further review. This identified 37 incidents related to vancomycin in Quarter 1, 2024.

Prescribing incidents accounted for over half of the identified incidents. Examples of prescribing incidents included:

• incorrect dosing (e.g. dose too high, especially for renal function; dose too low; no loading dose; no maintenance dose)
• duplicate prescriptions
• inappropriate target range
• dose prescribed in mg/Kg rather than the actual dose required

Administration incidents made up one third of the identified incidents. Examples of administration incidents included:

• incorrect frequency
• incorrect route
• rapid infusion leading, in two cases, to ‘Red Man Syndrome’, an anaphylactoid reaction characterised by upper body flushing

Monitoring incidents accounted for the remainder of the incidents and included failure to check levels before administration and failure to take levels at the correct time or at all, including in a neonate.

Figure 1: Examples of medication incidents involving vancomycin reported on NIMS in Quarter 1, 2024.

How to reduce the risk of incidents involving vancomycin

• The intravenous dose should be calculated in mg/Kg. The initial dose should be based on total body weight.³ Subsequent doses should be based on serum concentrations. Renal function must be considered when calculating subsequent doses
• In patients with normal renal function, serum concentration should be measured on the second day of treatment immediately before the next dose.³ In patients with renal failure, local guidelines should be consulted, or expert advice sought
• Prescribers should provide the actual dose required rather than stating the dose in mg/Kg
• Vancomycin powder in vials must be reconstituted and the resulting concentrate diluted prior to use
• Vancomycin should be administered as a slow intravenous infusion of at least one hour or at a maximum rate of 10mg/min³
• Vancomycin should not be administered by the intravenous route for Clostridioides difficile-associated diarrhoea or enterocolitis; similarly, vancomycin should not be administered orally for systemic infections due to poor absorption from the gastrointestinal tract

References available on request.