Medication errors, broadly defined as any error in the prescribing, dispensing, or administration of a drug, irrespective of whether such errors lead to adverse consequences or not, are the single most preventable cause of patient harm. Medication errors may be classified according to the stage of the medication use cycle in which they occur (prescribing, dispensing, or administration) although a recent classification of medication error into mistakes, slips, or lapses has been proposed. Incidences of medication error rates vary widely, as a result of the variety of different study methods and definitions used. The majority of medication errors occur as a result of poor prescribing and often involve relatively inexperienced medical staff, who are responsible for the majority of prescribing in hospital. Electronic prescribing may help reduce the risk of prescribing errors owing to illegible handwriting, although such systems can in turn lead to further problems such as incorrect drug selection, and their effect on patient outcomes requires further study. A multidisciplinary approach to solving the problem of medication errors is required which adopts an attitude of ` no blame', since incident reports have often been used as instruments of punishment, thereby creating a fear of discipline. This fear may be lessened by creating an open and safe environment for detecting and reporting medication errors. Current approaches to preventing medication errors are inadequate and require a shift in emphasis to a scientific investigation of preventable patient harm.
