Context: Prescribing errors involving medication dose formulations have been reported to occur frequently in hospitals. No systematic evaluations of the characteristics of errors related to medication dosage formulation have been performed.
Objective: To quantify the characteristics, frequency, and potential adverse patient effects of prescribing errors involving medication dosage forms.
Design: Evaluation of all detected medication prescribing errors involving or related to medication dosage forms in a 631-bed tertiary care teaching hospital.
Main outcome measures: Type, frequency, and potential for adverse effects of prescribing errors involving or related to medication dosage forms.
Results: A total of 1,115 clinically significant prescribing errors involving medication dosage forms were detected during the 60-month study period. The annual number of detected errors increased throughout the study period. Detailed analysis of the 402 errors detected during the last 16 months of the study demonstrated the most common errors to be: failure to specify controlled release formulation (total of 280 cases; 69.7%) both when prescribing using the brand name (148 cases; 36.8%) and when prescribing using the generic name (132 cases; 32.8%); and prescribing controlled delivery formulations to be administered per tube (48 cases; 11.9%). The potential for adverse patient outcome was rated as potentially "fatal or severe" in 3 cases (0.7%), and "serious" in 49 cases (12.2%). Errors most commonly involved cardiovascular agents (208 cases; 51.7%).
Conclusions: Hospitalized patients are at risk for adverse outcomes due to prescribing errors related to inappropriate use of medication dosage forms. This information should be considered in the development of strategies to prevent adverse patient outcomes resulting from such errors.