Antiretroviral prescribing errors in hospitalized patients

OBJECTIVE: To quantify error type and frequency and to identity factors associated with antiretroviral prescribing errors in hospitalized HIV-infected patients. DESIGN: Systemic evaluation of all medication prescribing errors involving antiretroviral medications between January 1, 1996, and October 31, 1998. Each error was concurrently evaluated for the potential to result in adverse patient consequences. Each error was retrospectively evaluated by three pharmacists and assigned a "likely related factor." SETTING: A 631-bed tertiary care teaching hospital. PARTICIPANTS: All physicians prescribing antiretroviral medications during the study period and all staff pharmacists involved in the routine review of medication orders. MAIN OUTCOME MEASURES: Type and frequency of prescribing errors involving antiretroviral medications and frequency of association of likely related factors to errors. RESULTS: A total of 108 clinically significant prescribing errors involving antiretrovirals were detected during the 34-month study period. The most common errors were overdosing and underdosing. Overall, errors occurred in 5.8% of admitted patients prescribed antiretroviral medications. The rate of error increased from 2% of admissions in 1996 to 12% of admissions in 1998. The most common likely related factors associated with errors were confusion/lack of familiarity regarding appropriate dosing frequency (30.3%) or dosage (25.5%), and confusion due to need for multiple dosage units per dose (13%). CONCLUSIONS: Hospitalized patients taking antiretrovirals are at risk for adverse outcomes due to prescribing errors. This risk has increased with the rising complexity of antiretroviral drug regimens. A limited number of factors are associated with a large proportion of antiretroviral prescribing errors. This information should be considered in the development of mediation error prevention strategies necessary to prevent adverse patient outcomes resulting from such errors.