Objective: To determine the rate and the primary types of medication dispensing errors detected by pharmacists during implementation of a unit dose drug dispensing system.
Setting: The central pharmacy at the Percy French military hospital (France).
Method: The check of the unit dose medication cassettes was performed by pharmacists to identify dispensing errors before delivering to the care units. From April 2006 to December 2006, detected errors were corrected and recorded into seven categories: unauthorized drug, wrong dosage-form, improper dose, omission, wrong time, deteriorated drug, and wrong patient errors.
Main outcome measure: Dispensing error rate, calculated by dividing the total of detected errors by the total of filled and omitted doses; classification of recorded dispensing errors.
Results: During the study, 9,719 unit dose medication cassettes were filled by pharmacy technicians. Pharmacists detected 706 errors for a total of 88,609 filled and omitted unit doses. An overall error rate of 0.80% was found. There were approximately 0.07 detected dispensing errors per medication cassette. The most common error types were improper dose errors (n = 265, 37.5%) and omission errors (n = 186, 26.3%). Many causes may probably explain the occurrence of dispensing errors, including communication failures, problems related to drug labeling or packaging, distractions, interruptions, heavy workload, and difficulties in reading handwriting prescriptions.
Conclusion: The results showed that a wide range of errors occurred during the dispensing process. A check performed after the initial medication selection is also necessary to detect and correct dispensing errors. In order to decrease the occurrence of dispensing errors, some practical measures have been implemented in the central pharmacy. But because some dispensing errors may remain undetected, there is a requirement to develop other strategies that reduce or eliminate these errors. The pharmacy staff is widely involved in this duty.