US Pharm. 2014;39(8)(Pharm&Tech suppl):8-12.

The pharmacist is entrusted with recording the drugs taken by the patient and counseling the patient regarding therapeutic necessity, interactions, and duplications. These responsibilities are required for ethical pharmacy practice and are not diminished when safe automated dispensing systems (ADS) are used to supply a patient’s medication therapy. ADS are a convenient way for patients to receive drugs, but only if a pharmacist and other caregivers are able to intervene, when needed, before administration of drugs received through such systems.

Devices of many types add efficiency to the distribution of patients’ medication. Policies and procedures for operating these systems are well documented in research and opinion articles. Boards of Pharmacy and regulatory agencies speak to pharmacist-directed use of ADS, and professional standards for other caregivers establish the responsibilities of those practitioners. Promotional materials from equipment vendors describe the benefits of use. However, the safety of ADS in the context of the entire medication process has not yet been shown conclusively.

The goal of this article is to describe the major features of ADS and to define areas of interfacing in the medication process where the potential for errors can be recognized and minimized. Understanding the entire medication process helps pharmacists design the best system for a healthcare setting and offer the best counsel to caregivers and patients about how to use the system. This article includes an overview of ADS, aspects of the medication process, interface issues between parts of the medication process, and current pharmacist-directed functions for the safe use of ADS.

Overview of ADS

In the 1980s, many dispensing devices and systems were being developed in response to research concerned with dispensing errors in a typical pharmacy of that time.1-4 By the 1990s, ADS were numerous enough to be the subject of review articles, especially given the significance of these devices in achieving the efficiencies required in managed care environments.5 Although the safety of individual components of ADS, such as packaging machines, dispensing cabinets, and controlling software, could be easily demonstrated, little reproducible evidence existed that the combination of components needed for ADS resulted in a safe overall system. Studies highlighted human errors such as mislabeled drug packages, improperly filled dispensing cabinets, administration of correctly labeled drugs to the wrong patient, and failure to adequately monitor the effects of drug administration. Safety studies of the medication process referred to the safety record and procedures of the airline transportation industry as an example of the best safety model. The “Swiss cheese” model of error—wherein the lineup of holes in multiple slices of cheese illustrated how an error could penetrate a system—was often used to define the sources of errors within a system. The problems were often failures at interface points between ADS components.

Institute of Medicine reports on errors and early evidence of medication errors due to ADS failures have driven the pursuit of safety.6,7 Pharmacists have the legal and professional obligation to ensure that ADS are safe, accurate, and secure and to provide patient confidentiality. The safest ADS should meet the needs of all caregivers.8 More recent work has focused not on the incidence rate of dispensing errors, which is relatively low compared with other categories of errors, but on large increases in the number of doses dispensed via ADS that result in a large number of errors, even with a relatively low incidence rate.9

Three broad categories of ADS exist: centralized, decentralized, and point-of-care. Centralized systems have a pharmacist in direct control of the dispensing process. When a drug order is received, the order is interpreted by the pharmacist and entered into a software program; potential interactions or adverse outcomes are evaluated; a drug package is generated; a label is printed; and the label is attached to the package. Depending upon the particular rules of the legal jurisdiction where this is done, various methods are employed to ensure that the finished prescription is correct in all respects and is dispensed properly.

Decentralized systems often exist outside of the pharmacist’s immediate control, but the pharmacist must still ascertain that the various steps are correct. These steps include ensuring that the correct drug dose is available in the correct location in a dispensing cabinet; that the caregiver accessing the storage cabinet is authorized to do so; and that the dose is accurately administered to the correct patient. Decentralized systems are used as a source of the patient’s first dose or the entire drug supply. The pharmacist, although distant from actual drug distribution, is able to control the system by various means, such as limiting the removal of doses if an active drug order does not exist in the pharmacy’s drug profile.

Point-of-care systems are similar to decentralized systems. However, the pharmacist may not be aware of a drug order when a dose of medication is removed from the system.

These systems require specific guidelines for override features when a drug is removed by a caregiver before the pharmacist receives, evaluates, and enters a drug order. Regulations of authorities such as Boards of Pharmacy and the Joint Commission on Accreditation of Healthcare Organizations require a retrospective review of the drug order by the pharmacist, often specifying the time frame in which the review must occur. The progress of ADS development has mimicked the repurposing of pharmacy software. In its original form, pharmacy software was primarily designed to bill for pharmacy services. The flow of pharmacy billing data into a care facility’s accounting system was an initial interface obstacle. Continuing development of ADS has morphed pharmacy software into a relatively seamless control mechanism for the entire medication process.

To summarize, the development of ADS attempts to be consistent with three goals: the pharmacist’s commitment to direct patient care, the reduction of costs, and the incorporation of rapidly developing technology into a safe medication process. The National Association of Boards of Pharmacy (NABP) Model Pharmacy Act provides a recommended basis for pharmacy practice and a good definition of automated pharmacy systems.10 In many hospitals, ADS have entirely replaced the 24-hour (or more frequent) daily cart exchanges that represented the state of hospital pharmacy practice after floor-stock systems and multiday supplies or multiday cart exchanges were abandoned.

Aspects of the Medication Process

The safest ADS will provide drugs and achieve the “five rights”—right patient, right drug, right dose, right route, and right time—for every administered dose. Driven by a complete patient drug profile, ADS have the potential for safety.

It is extremely difficult to prove that various available devices or systems of devices are as safe as possible. There are a number of reasons for this. Systems used in one care area may not function as safely when used in other care areas. There is little consistency about exactly what is measured or how errors are defined within safety studies. It is unlikely that safety studies are blinded, and not all studies use statistical analysis of findings. Aside from computer technology, changes in work practices most likely have contributed to the safety of the medication process. Therefore, the only way to know what is best for a particular patient-care environment is to determine exactly what is expected of the system for that care unit. Relying on a one-size-fits-all system or on the opinion of the seller of a system often results in the system operating below expectations in day-to-day use.

Considerable time is needed to plan ADS. The Health Level Seven (HL7) International interface protocol for the exchange, integration, sharing, and retrieval of electronic health information provides flexibility.11 Thus, it is possible to tailor a customized ADS. Some vendors charged large fees to build a customized system for interfaces with other vendors’ devices. Now there is sufficient competition that vendors are much more realistic about these fees.

Further improvement of ADS now involves including point-of-care medication order entry; complete control of medication movement from acquisition and packaging to administration using bar coding (or radio-frequency identification chip or other identification and data-capture technologies); establishment of a single location for viewing and recording patient history, clinical data, and progress notes; and control of parenteral injection devices by linkage to the pharmacy’s drug profile.12 Whether the expense and contribution to patient safety of these added technologies are worthwhile is the subject of ongoing research.13 Appraisals of the pros and cons of ADS are available.14

Interface Issues

A competent interface between the software controlling a dispensing cabinet and the software allowing clinical support by the pharmacist is fundamental for safe ADS. Additionally, the need for competent interfaces within the entire medication process (ordering, dispensing, administering, monitoring) requires interfaces with other software operating in support. Examples include software that controls patient admissions, transfers, and discharges; supports pharmacy billing; controls bar-coding technology; controls direct prescriber order entry; controls charting of all patient information in one system used by all caregivers; and validates the education and competency of caregivers who use ADS. A strategic plan outlining the relationship between these interfaces and a timetable for implementing them are crucial to achieving safe ADS. The plan should represent all parts of the medication process, including the support functions.

Core processes for the safe use of dispensing cabinets have been described.15 These focus on using cabinets driven by the pharmacy drug profile, so that (with certain exceptions) a dose can be removed only when an order exists in the profile. Controlling the ability to override the system by removing a dose when no order exists is a major step toward achieving a safe system. Interfaces for bar-coding drug doses are also important to meet the highest safety standard. Reading the bar code on doses of drugs when they are packaged, when refilled in a cabinet, and when removed prior to administration helps achieve safety. The use of bar-coded, unit dose–packaged drugs contributes to safety by allowing positive identification if a dose is returned, permitting a final validation of dosing using a medication administration record generated by the ADS, and allowing creation of security documents, such as controlled-substances inventory records.

The safety of including point-of-care drug order entry by prescribers in ADS is problematic because the interface between the software controlling prescribers’ actions and that controlling creation of the pharmacy’s drug profile is extremely complicated. One complaint often voiced involves the large number of choices for selecting the correct drug. Pharmacy software displays not only many different dosage forms of a drug, but also many different brands or generic versions of dosage forms. One extremely labor-intensive solution to this problem is to create a mini-formulary—an order set that represents doses or combinations of doses most often prescribed by an individual practitioner—for each prescriber. Also labor-intensive, but an approach that is consistent with bringing the pharmacist’s clinical expertise to the patient’s care unit, is to have a pharmacist work directly with caregivers to enter orders when therapeutic decisions are made. As point-of-care systems develop more fully, formularies can be managed more closely and prescribers can become more familiar with order entry. ADS developed through strategic plans that closely coordinate the interests of all caregivers and all interfacing issues are key to achieving fully integrated software packages.

Pharmacist-Directed Functions

Developing a strategic plan for ADS is perhaps the most important phase in system design, and the pharmacist should take a lead role. The pharmacist operates under strict ethical and regulatory guidelines, and this role is complex. The pharmacist should ascertain that nothing in the plan minimizes the bar-coding flow through the entire medication system, from inventory acquisition and packaging to point-of-care dose administration. Strict compliance with policies and procedures governing who stocks a dispensing device, how the act of stocking is certified, and whether and how doses may be returned to the dispensing cabinet must be ensured.

The pharmacist should remain as close as possible to patient care on a care unit to minimize disruptions as the system is used and to facilitate order entry. The pharmacist should also ensure that the strategic plan includes tight formulary management in order to eliminate the frustrations of trying to include an impossible number of dosage forms in dispensing cabinets. The pharmacist should include concrete mechanisms for dispensing outlier drugs not stored in a dispensing device while making sure that bar-coding control is not compromised. It should be ensured that all caregivers completely understand which first-dose and as-needed drugs are available in the ADS. The pharmacist must also see to it that complete and workable policies and procedures govern the occasions when it is permissible to override the system to obtain emergency doses.

The strategic plan should represent the work of all caregivers involved and must be carefully designed to include all steps in a care unit’s medication process, including consideration of the hardware necessary for the safest system. It is important, however, to ensure that hardware issues do not overwhelm more fundamental needs. It may be tempting to purchase an off-the-shelf system, but in many cases these systems seem impressive because of the hardware technology included in the package. It is far better to design the physical system by looking first at strategic planning and the available software. Entering “formulary management” or “formulary management software” into a search engine will retrieve details on the sophisticated information-handling software that, with HL7 interfacing, can operate ADS. This is not to minimize the importance of quality hardware; however, the recent advances in automation technology have occurred though software design. Certainly, manufacturing technology has compressed enormous memory and function into very small devices, but the software is what creates the magic.


The focus of this article has been on improving the safety of the medication process using ADS. Human frailty is always a potential cause of error. By designing ADS to have as many caregivers as possible check the flow of events in the medication process, errors can be recognized and minimized through a carefully developed strategic plan. ADS that are carefully planned to use competent interfaces and feedback mechanisms have a better chance of being truly safe. It is now quite apparent that pharmacists’ services go well beyond drug-purchase control, drug dispensing, and drug recordkeeping. Pharmacists’ clinical services are respected, and integration of these services with the patient-care efforts of other caregivers will produce the safest system for drug distribution.


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