Objective: To evaluate the chemotherapy error prevention system of Songklanagarind Hospital by utilizing the medication error reports.

Design: Retrospective descriptive study Materials and methods: The chemotherapy medication error reports from January-June 2006 were reviewed. Type and severity of errors were considered to evaluate the efficacy of the system used to prevent chemotherapy medication errors.

Results: From 296 reports (202 patients), there were no reports of error in chemotherapy that have the created prevention system from previous reports in the literature. The severity of medication errors in this study were A and B only that mean no error reach the patient. There were 291 reports of prescribing errors, 1 report of admixing error and 4 reports of dispensing errors. Inappropriate dosage orders in individual patients was the most common type of prescribing error. Most reports of incorrect quantity orders originated in the outpatient department. No reports of untreated indication in inpatient department that have computerized protocol were found.

Conclusion: Every hospital should emphasize the importance of developing a system for preventing medication errors in cytotoxic dispensary services. For patient safety goals,the type and cause of medication errors have to be reviewed and analyzed by a multidisciplinary team in order to develop the system.