Prescribing errors resulting in adverse drug events: how can they be prevented?

As approximately 19% of medical errors occurring in hospitals are related to medication errors, reduction of these is one of the major goals to be achieved by healthcare providers. Medication errors may occur at different levels: i) prescribing; ii) transcription; iii) dispensing; and iv) administration. Whereas errors in transcription can be significantly reduced by computerised physician order systems, improvement of prescribing appears to be a much larger problem. Continuous support by ward pharmacists may be feasible in some hospitals, but not in the setting of ambulatory prescribing. Much hope relies on computerised physician order systems with a knowledge database for interactions, warnings on allergies and other intelligent alerts. However, these systems still have some shortcomings and it has not yet convincingly been shown that the use of this technology really improves patient safety.