Background Administering the wrong drugs is one of the most common medication errors in Denmark. A system for reporting adverse events has revealed that use of unsuitable or differing drug labels leads to medication errors in Anaesthetics and ICU wards at the Danish North Region Hospital.

Purpose To develop a colour-coded drug labelling system to improve patient safety in Anaesthetic and ICU wards at the Danish North Region Hospital.

Materials and methods A literature study was conducted to identify recommendations regarding colours and designs of drug labels. The search terms drug labelling, user-applied drug labels and syringe labelling were used. Legal requirements and international standards for user-applied anaesthetics labels were ascertained. Qualitative input from clinicians was collected from the anaesthetic and ICU wards by e-mail.

Results New standardised drug labels complying with national legal requirements were designed.

The labelling design addresses a number of elements contributing to medication errors:

• ▶ Trade name and strength have a prominent placement and are emphasised in bold.

• ▶ Drugs with similar names are differentiated using ‘tall man letters’ for example epinephrine and norepinephrine.

• ▶ Size of drug label is adjusted to different sizes of syringes.

• ▶ Colour code reflects the effect of the drug for example blue signal opioids while yellow indicate induction agents.

Further procedures have been established for assessing compatibility in practice, and for updating the labels as trade names change due to adjustments in drug supply.

Conclusions The labels were successfully designed and brought into use. Whether the patient safety has actually improved will be evaluated by assessing the number of reports of adverse events involving drug labelling.