Streamline the ADC Override List

June 2022 - Vol.19 No. 6 - Page #2
Category: Automated Dispensing Cabinets

Automated dispensing cabinet (ADC) technology is widely utilized in health care institutions, as evidenced by its adoption in 91% of hospitals.1 Hospitals leverage these devices to achieve a number of goals, including streamlining pharmacy workflows, improving medication access in patient care areas, and supporting pharmacy inventory management. The implementation of ADC technology also provides significant safety benefits, including a reduction in medication dispensing errors and electronic tracking of controlled substances to deter drug diversion.2

Despite the benefits ADCs provide, opportunities for errors still exist. One of the major risks associated with ADCs is the inappropriate use of medication overrides. An ADC override is defined as the process of bypassing the pharmacist’s review of a medication order to obtain a medication from the ADC when assessment of the patient indicates that a delay in therapy would harm the patient.2 The risk increases when practitioners view the override process as a routine part of their workflow and fail to recognize the inherent risks.

Establish Best Practices

The Institute for Safe Medication Practices (ISMP) has received multiple reports of harmful and fatal medication errors that involve removal of medications using the override feature of an ADC.3 To mitigate this risk, ISMP recommends organizations limit the variety of medications that can be removed from an ADC using the override function to only those medications that would be needed emergently (as defined by the organization). ADC overrides should be monitored to verify safe use of the functionality, and the list of medications available using the override function should be periodically assessed for appropriateness.3

While the value of an organization-specific override list is clear, creating that list can be challenging. The American Society of Health-System Pharmacists (ASHP) provides a practical resource for establishing a list of medications available through an ADC override in inpatient care settings.4 Start by assessing life sustaining medications, medications where a delay related to pharmacist review may result in potential patient harm, and medications considered antidotes or reversal agents for override applicability. Medications that might be urgently needed for comfort measures, such as acute pain relief or nausea and vomiting, may also meet the organizational criteria for emergent need.

In addition to evaluating the individual medications, it is important to establish appropriate risk reduction strategies to mitigate potential harm. Such strategies may include limiting the strength or quantity of medications available via override, providing readily available preparation and dosing guidelines, and optimizing the alerts generated when utilizing the override functionality.4

Conduct a Baseline Assessment

The Hospital of the University of Pennsylvania is a large academic medical center located in Philadelphia, Pennsylvania with more than 800 licensed inpatient beds. ADCs are widely utilized throughout the hospital to provide access to necessary medications. The list of medications available through the override function is managed by the Medication Safety Committee and updates are presented to the Pharmacy and Therapeutics (P&T) Committee for final approval. The override list is reviewed in its entirety by both the Medication Safety Committee and the P&T Committee at least annually.

Previously, the hospital maintained multiple site-specific lists of medications available via override, including a general override list, an emergency care override list, a critical care override list, and a labor and delivery override list. Facility wide, all ADCs were programmed to allow for removal of the medications on the general list via override. ADCs in the emergency department (ED) were designed to allow for the additional removal of those medications on the emergency care list via override. Similarly, ADCs in the intensive care units (ICUs) and the labor and delivery (L&D) department were programmed to allow for removal of medications on the critical care and labor and delivery lists, respectively.

This model allowed us to closely limit the clinical locations where a medication could be removed without a verified clinical order. Yet many clinicians found this system confusing as it was not always clear if a medication would be accessible via override. In addition, some units (eg, step-down units) did not fit neatly into one of the four categories, which occasionally prevented appropriate use of the override feature. Lastly, the expanding use of surge units and increasing need for flexible care units resulted in the presence of patients who require a higher level of care than the unit typically serves. In many cases, a medication loaded into the unit’s ADC was needed urgently; however, it was not readily accessible due to our site-specific list design.

Develop a New Override List

To address these concerns, we decided to streamline the ADC override strategy and utilize a single, standardized ADC override list. To accomplish this, a small team led by the medication safety clinical pharmacy specialist combined the medications from each of the previous override lists into one master list. Each item on the list was then assessed and assigned to one of four categories:

  • Life sustaining medications
  • Antidotes/Reversal agents
  • Administration delay could lead to harm
  • Comfort care (pain/nausea) medications

Once each medication was categorized, we made recommendations to simplify the list as appropriate. In some cases, an override medication was limited to a single strength or to a single medication from a therapeutic class on the list. To support these recommendations, we also reviewed 90 days of ADC override data. This step was critical to understanding the utilization patterns and anticipating any potential impacts when removing a medication from the list.

Historic morphine utilization patterns demonstrated an opportunity for simplification, as the master list originally contained two strengths of morphine: 2 mg/mL injection syringe and 4 mg/mL injection syringe. Over a 90-day period, the morphine 2 mg/mL injection syringe was overridden 82 times, while the morphine 4 mg/mL injection syringe was overridden 131 times. After reviewing the locations of these overrides, we found the morphine 4 mg/mL injection syringe was overridden almost exclusively in the ED, while the morphine 2 mg/mL injection syringes were overridden across various units throughout the hospital. We did not want nurses to have to administer a partial dose after an override, given the risk of overdose if the full syringe is accidently administered. In addition, when a dose of morphine 4 mg IV was needed, two morphine 2 mg/mL syringes could be administered. Thus, we recommended removal of the morphine 4 mg/mL injection syringe from the override list.

The proposed override list was brought to the Medication Safety Committee for extensive review and approval. Each category of medications was scrutinized by the interdisciplinary committee, with thoughtful discussions focusing on common practices and potential scenarios. The 90-day ADC override data was also provided, along with the rationale for each medication removal. Once this process was complete, each member of the Medication Safety Committee was encouraged to share the proposed list with staff members in their care areas to elicit feedback. Through this secondary review process, we were able to identify and recommend other key medications and formulations for override list inclusion. These additional recommendations were presented at the following Medication Safety Committee meeting, where they were incorporated into the final proposal and approved. Final review and approval of the proposed override list was completed at the next P&T Committee meeting.

List Implementation

An educational tip sheet about the ADC override list updates was developed for pharmacy and nursing staff. The tip sheet explained how the new override list was developed, highlighted the key changes, and detailed the process for requesting changes or additions to the list. The new list was placed on the online hospital formulary to ensure easy access for all staff members.

Implementation of the new override list was coordinated with the pharmacy automation team. Prior to the go-live, each ADC was assessed to ensure the correct formulation and/or strength of an approved override medication was loaded into the cabinet. The team also ensured that appropriate stock was available to support anticipated need. Once the preparations were complete, a go-live day was selected and communicated to all staff members. Following go-live, the voluntary event reporting system was closely monitored for events involving a delay in access to medication to determine if there were any impacts from the override list changes. Monitoring continued for about 90 days following implementation. To date, there have been no events where lack of override access was a contributing factor.

Ongoing Maintenance

Requests for changes to the override list are made in writing to the co-chairs of the Medication Safety Committee. The requestor attends the next Medication Safety Committee to present their proposed addition or removal, and the committee carefully evaluates the request. The committee’s process encompasses assessing whether the medication is needed for a truly emergent situation, considering any potential harm that may occur if pharmacist review is bypassed, and identifying additional safety precautions that may be needed.

Each year, the override list is reviewed in its entirety by the Medication Safety Committee to determine if changes are needed. During this annual review, ADC override data is utilized to review commonly overridden medications, unit-specific override rates, and the documented rationales for override utilization (rationale options include; Emergency/Code/Rapid, Intubation, Hemodynamic Instability, Metabolic/Electrolyte, Patient Own Medication, Critical Override, and Other). The proposed changes are discussed and approved by the Medication Safety Committee members and then sent to the P&T Committee for final review and approval.

Override Monitoring

ADC overrides are assessed on a regular basis to ensure safe use of the functionality and to determine if modifications are needed. On the units, the charge nurse runs the override report at the end of each shift to review the appropriateness of each override withdrawal. Inappropriate medication overrides are discussed with the nurse involved and feedback is provided as appropriate. The medication safety clinical pharmacy specialist reviews override data on a monthly basis to identify trends and conduct investigations as needed. Lastly, the medication safety clinical pharmacy specialist presents a quarterly analysis to the Medication Safety Committee. Smaller workgroups are developed as needed to address any unit-specific concerns.

Since the implementation of the new list, our facility-wide override rate has decreased from 1.22% (December 2021; 4,498 overrides out of 368,344 total transactions) to 0.89% (March 2022; 3,455 overrides out of 384,233 total transactions).


The safe use of ADCs relies, in part, on judicious use of the override function. Best practices and guidance documents, such as those provided by ISMP and ASHP, can help teams develop a concise, yet comprehensive, override list for their facility. Medication inclusion should be based on a systematic review by an interdisciplinary team to determine if the benefit of unrestricted access outweigh the risk of potential harm. Finally, overrides should be monitored regularly to assess for appropriate use and to identify when updates are needed.

Melissa Augustino, PharmD, BCPS, is the medication safety clinical pharmacy specialist at the Hospital of the University of Pennsylvania in Philadelphia, Pennsylvania. She received her doctor of pharmacy degree from the University of Maryland School of Pharmacy and completed her PGY-1 pharmacy practice residency at Howard County General Hospital. Melissa also completed a PGY-2 in medication-use safety at the Johns Hopkins Hospital in Baltimore, Maryland.


  1. Halvorsen D. State of pharmacy automation 2021. Pharm Purch and Prod. 2021;18,8:54-55.
  2. Institute for Safe Medication Practices (ISMP). ISMP Guidelines for the Safe Use of Automated Dispensing Cabinets. 2019. Accessed May 1, 2022.
  3. Institute for Safe Medication Practices (ISMP). ISMP Targeted Medication Safety Best Practices for Hospitals. February 9, 2022. Accessed May 1, 2022.
  4. ASHP Section of Inpatient Care Practitioners. Practice Resource for Automated Dispensing Cabinet Overrides. Accessed April 8, 2022.


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