ing can be particularly difficult when consumers use multiple pharmacies to fill their prescriptions and fail to communicate this to each pharmacy.
Depending on the specific order and patient, preparation of the medication may require counting, measuring, or compounding (mixing of ingredients); repackaging (e.g., unit doses); and labeling. Activities associated with preparation present the greatest opportunity for error within the pharmacy (Manasse and Thompson, 2005). Most inpatient errors involve selection/ dispensing of an incorrect drug (e.g., because of sound-alike, look-alike names or packaging), dosage strength (e.g., incorrect dilution), formulation (e.g., tablet versus intravenous), or dosage calculation (e.g., incorrect calculation of flow rate for intravenous medication) (Cohen, 2000; Phillips et al., 2001). Outpatient errors tend to center on incorrect drug labeling information (e.g., use or administration of the drug) (Buchanan et al., 1991; Flynn et al., 2003).
During preparation, a large percentage of oral and injectable medications used in the inpatient setting require further manipulation (compounding and/or repackaging) prior to administration, increasing the risk of error. Most drugs are licensed for adult use; reformulation and compounding are most often necessary to treat neonates or pediatric patients who cannot swallow tablets or capsules and require dosage concentrations and formulations tailored to their age, body weight, and body surface area (Nunn, 2003). Adult patients with a rare condition for which an orphan drug9 is no longer manufactured may require the pharmacist’s expertise to compound and formulate a medication from chemicals and ingredients available only in bulk (Kastango, 2003). Also, repackaging is common for inpatient facilities so as to provide medications in unit doses and thereby minimize dose manipulation and errors at the bedside. Currently, 79 to 99 percent of hospital pharmacists repackage oral medications, and 29 percent repackage injectables (Cohen, 2000; Pedersen et al., 2003). However, new federal regulations to go into effect in 2007 require manufacturers (or third-party repackagers) to provide all products to hospitals in unit dose form with bar codes (FR, 2004b). In a further effort to decrease errors, some hospitals also use decentralized automated dispensing systems (e.g., ward-based cabinets) for storing certain medications that are in unit dose form (e.g., narcotics, as-needed drugs, limited floor stock) (Cohen, 2000). These systems can be accessed by nurses with “swipe cards” or personal identification numbers. Finally, a growing number of community-based and most mail order pharmacies are using automated dispensing systems, including centralized systems that can produce unit doses (e.g., via strip or envelope packag-