• High workload/low staffing is the primary contributing factor to medication errors associated with preparing and dispensing medications in both community and institutional settings (Davis and Cohen, 1994; Roberts et al., 2002).

• Interruptions (temporary cessation of prescription filling) and distractions (external stimulus without cessation of prescription filling) are highly correlated with dispensing errors (Flynn et al., 1999). Error rates per half hour of 6.65 percent for interruptions and 6.55 percent for distractions were found, with incorrect instructions to the patient being the most common error. About 26 percent of pharmacists’ time is spent dealing with issues (interruptions) related to third parties and miscellaneous administrative tasks (NACDS, 1999).

• Product labels are often read under less-than-ideal conditions, and the way a medication is packaged and labeled can have a significant impact on error rates. Problematic aspects of packaging and labeling include look-alike packaging, obscure placement of critical safety information, and print that is too small and lacks sufficient distinctions in contrast or boldness (Cohen, 2000; Phillips et al., 2001; IOM, 2000, 2004c; USP, 2004).

• Improper lighting, inadequate counter space, poor placement of telephones, and uncomfortable temperature and humidity create a work area that can negatively affect workflow from one task to another and contribute to errors caused by clutter or contamination (Cohen, 2000).

• Drug reference files, texts, and/or database systems may not be current, resulting in errors associated with outdated and incorrect information (Cohen, 2000). Constant updating of drug information is particularly critical to patient safety given the limited data available when medications enter the market and the amount of new data on medications already in use among the population.

Nurses have primary responsibility for administering medications in acute care hospitals, in long-term care facilities, and during home care. In certain instances, a nursing assitant/technician may be permitted to administer selected medications (Munroe, 2003; Castle and Engberg, 2005). In many of these settings, the environment for nurses is demanding, characterized by long work hours, staffing shortages, high patient and staff turnover, and constant interruptions (O’Shea, 1999; IOM, 2004b; Jenkins and Elliott, 2004; Suzuki et al., 2005). Accurate administration of medications can be challenging in this environment.

Tasks associated with preparing medications for administration can range from simple retrieval of a unit dose from a ward-based automated dispensing system to reconstitution of a powder with a sterile diluent