Featured Articles

A Comprehensive, Proactive Plan Is Needed to Mitigate Risk When Changing Drug Concentrations

Problem: Errors related to a medication’s concentration have been reported to ISMP, particularly when multiple concentrations exist. These errors are more prevalent during transitions in patient care and when switching to an alternative product with a different concentration, including during a drug shortage. We have previously published many of these errors, as well as the risks associated with concentration changes in commercially available products. For example, in our last newsletter, we wrote about the risk of errors as healthcare providers transition patients to the recently approved EPRONTIA (topiramate) 25 mg/mL oral solution, which differs from common pharmacy compounded topiramate concentrations of 20 mg/mL for adults and 6 mg/mL for children. We also warned practitioners about a new formulation of baclofen oral suspension, FLEQSUVY (25 mg/5 mL), which differs in strength from another brand of baclofen oral solution, OZOBAX (5 mg/5 mL), used for the same purpose. We recommended standardizing to a single concentration, when possible, and establishing a comprehensive, proactive concentration change plan to prevent undesirable consequences, including errors, during the conversion.

The American Society of Health-System Pharmacists (ASHP) Standardize 4 Safety initiative is a national, interprofessional initiative that has created several standardized concentration lists. To date, the initiative has provided lists of standard concentrations for many adult and pediatric continuous medication infusions, and oral liquid medications. Additional lists are coming soon. Healthcare providers are encouraged to adopt these standardized concentrations to decrease the risk of medication errors, increase provider efficiency, and improve patient outcomes.

Recent Errors During Concentration Changes

Medication errors, including serious under- and overdoses, can happen if organizations overlook even the smallest details when converting to a new concentration. Two recently reported errors illustrate this risk.

Case 1

A hospital pharmacy that had been compounding intravenous (IV) milrinone (100 mcg/mL) infusions for heart failure patients decided to switch to commercially available, ready-to-use premixed bags with a different concentration (200 mcg/mL) to reduce the risk of a pharmacy preparation error, improve efficiency, and differentiate the standard milrinone concentration from a much stronger concentration (1 mg/mL) that the pharmacy also compounded for fluid-restricted patients. The pharmacy coordinated the conversion in various computer systems, including the electronic health record (EHR), pharmacy technologies and IV workflow systems, and the smart pump drug library. Soon after switching to the 200 mcg/mL concentration, an intensive care unit (ICU) nurse received a patient from the operating room (OR) with a milrinone infusion. When she tried to put the milrinone infusion on a smart infusion pump, she realized that the infusion must have been prepared using the old concentration, 100 mcg/mL. Investigation of the event identified that anesthesia staff used a separate anesthesia-specific documentation system that had not been updated to the 200 mcg/mL concentration.

Case 2

A wholesaler notified a hospital pharmacy that an over-the-counter (OTC) antidiarrheal medication, loperamide 1 mg/5 mL (0.2 mg/mL) oral solution, was being discontinued. So, the pharmacy purchased another loperamide oral solution with a different concentration of 1 mg/7.5 mL (0.13 mg/mL). Communication about the change was shared with staff, computer systems were updated, and patients were switched to the new concentration. Staff thought that all bottles containing the discontinued concentration had been removed from the pharmacy and discarded. While checking an oral solution batch of loperamide a few weeks later, a pharmacist discovered that a bottle of the discontinued loperamide concentration (1 mg/5 mL) had been used to fill oral syringes that were labeled with the new loperamide concentration (1 mg/7.5 mL). Barcode scanning was not available in the pharmacy to detect the error, and because only one concentration was typically available, pharmacy staff had not noticed the concentration difference. Doses from a batch of oral syringes had already been dispensed from the bottle the previous day, resulting in several patients receiving almost twice the intended dose. These patients were monitored, and no harm was noted. Investigation of the event determined that a bottle of the 1 mg/5 mL oral solution in the overstock area had not been discarded and was used.

Safe Practice Recommendations: Whether adopting the standard concentrations promoted by Standardize 4 Safety or exploring a change that requires a different medication concentration, consider the following elements of a comprehensive, proactive concentration change plan to prevent confusion and medication errors.

Select a Conversion Team

  • Commission a small, dedicated team with representation from inpatient pharmacy, informatics, nursing, medical staff, and other disciplines (e.g., anesthesia staff, outpatient pharmacy, respiratory therapy, clinical nutrition, emergency medical services) as needed when a concentration change is necessary in your organization. Have the team plan, implement, monitor, and sustain each change. Involving an interdisciplinary team enhances collaboration across disciplines; improves the readiness of health systems to make a change; results in more efficient, higher-quality implementations; and sustains the change through mentoring and prompt problem-solving.1 

Determine Feasibility

  • Assess the ease of procuring or compounding the new concentration, considering the cost, required resources, and whether this will be a temporary or long-term change.

  • Have the team review the medication’s normal dose range as well as outliers (patients on higher or lower than typical doses) to ensure the new concentration is feasible for your organization. For example:

    • If you are considering a more concentrated infusion, will there be any smart infusion pump low-rate limitations that would prevent the practitioner from being able to program and administer the dose as patients are being weaned off the medication?

    • If you are considering a more diluted concentration, could this result in any patients receiving too much fluid volume?

    • You may be required to make a product change with a different concentration during a drug shortage, despite limitations; in that case, the team can determine whether it is feasible to sustain the concentration change after the drug shortage has been resolved.

  • If your organization plans to transition to the standard concentrations in Standardize 4 Safety, use a phased approach to make the conversions due to the numerous systems involved and various actions needed to prevent an error during the transition. Have the team prioritize the medication concentrations that require updates, managing just one product change at a time.

Plan the Change

  • Involve frontline staff to identify which systems will be impacted by the concentration change and anticipate the necessary modifications. For example:

    • Review standard concentration references, related policies and procedures, master formulation records for extemporaneously compounded products, and patient teaching materials, to determine any necessary modifications.

    • If the medication is on your automated dispensing cabinet (ADC) override list, does a safety review show that the new concentration may warrant removal from the list? Will the new formulation fit into the allotted ADC compartment?

    • Do prescribing systems/EHRs, medication administration records (MARs), and/or smart infusion pump drug libraries require modifications? Depending on your organization, there may be certain electronic systems (e.g., stand-alone prescribing systems) and unique devices (e.g., smart pump drug libraries) used in perioperative areas, the emergency department, radiology, catheterization laboratory, dialysis department, and other specialized areas that will need to be updated separately.

    • Evaluate areas and technologies in the pharmacy where the concentration will need to be modified, including inventory system software, automated compounding devices, IV workflow management systems, master formulation records, robotics, radio frequency identification (RFID) systems, unit dose packaging templates, the controlled substance safe, and ADCs.

    • Do any emergency or critical care reference guides (e.g., critical care tables, code binders) used during rapid responses or other emergencies need to be modified?

    • For concentration changes of stock medications or infusions, where is the current supply of the older concentration stored, how can you coordinate the swapping out of all stock, and where should the new product exist outside the pharmacy?

  • Prepare and validate conversion charts (electronic or manual) for each concentration change.

  • Plan for and test the barcode for each new medication concentration that will be needed with pharmacy inventory, preparation and dispensing software, and bedside barcoding technology.

  • For each concentration modification, determine the key practitioner types that should be involved in the decision-making process, along with required committee approvals.

  • Determine a go-live date for the concentration change in advance, if possible. Changing a concentration due to a drug shortage may require a hurried go-live date; however, other concentration changes should allow for a scheduled go-live date. Avoid go-live dates just prior to a weekend or holiday.

  • Establish a communication and staff education plan to alert all involved practitioners about the concentration change and go-live date.

  • Establish a plan to identify all patients with current, held, or future inpatient orders for the medication that will need to be converted to the new concentration.

    • If your organization has an outpatient pharmacy, identify in the computer system all outpatients who currently receive the old concentration of the medication to ensure all active outpatients are converted to the new concentration within a defined period of time.

  • Before a patient transitions from inpatient to outpatient, develop a patient education plan if there is a change in the required volume of their medication taken at home.

    • In outpatient pharmacies, consider tagging prescriptions for medications with a concentration change for mandatory patient education.

Implement the Change

  • Initiate the communication and staff education plan.

  • Coordinate the removal of old stock located in areas identified during planning (e.g., central pharmacy, satellite pharmacies, overstock areas; patient care unit storage locations such as patient-specific bins or drawers, ADCs, code carts).

  • Provide the medication in the new concentration to locations identified during planning.

  • Activate the new concentration and deactivate the previous concentration in all electronic systems as anticipated during planning.

  • Run a report of all active, held, and future orders to identify patients currently prescribed the medication.

  • Work closely with nursing staff prior to converting all active patients to the new concentration and coordinate any required modifications to administration times.

  • Require new orders that discontinue the old concentration and start the new concentration so the MAR reflects the new concentration. (The timing of this should be coordinated with the distribution of the new concentration and removal of the old concentration.) 

  • Using the teach-back method, communicate with patients and/or caregivers about the new concentration, the corresponding volumetric dose, and how to measure each dose of an oral liquid medication with an oral syringe. Also, teach home infusion patients or their caregivers about programming changes for their infusion pumps.

  • As applicable, collect information on the strength of concentrations during medication reconciliation when a patient is admitted.

  • Validate that discharge paperwork and prescriptions reflect the new concentration.

Sustain the Change

  • Run a follow-up report to check that patients who have been prescribed medications in the previous concentration have been updated to the new concentration.

  • Engage in safety walkarounds in the pharmacy and all affected patient care units to gather feedback, answer questions, troubleshoot any issues, and mentor practitioners through the concentration change.



  1. National Implementation Research Network. Framework 4: implementation teams. In: NIRN. Module 1: An Overview of Active Implementation Frameworks. The University of North Carolina at Chapel Hill; 2021.


Suggested citation:

Institute for Safe Medication Practices (ISMP). A comprehensive, proactive plan is needed to mitigate risk when changing drug concentrations. ISMP Medication Safety Alert! Acute Care. 2022;27(12):1-4.