Cost-Benefit Analysis of Fentanyl Vial Size in the Emergency Department

Fentanyl is a commonly utilized opioid within the emergency department (ED) for the management of acute pain. Fentanyl is supplied as 50 microgram (mcg)/1 milliliter (mL) and 100mcg/2mL vials, with each vial utilized for single-patient use. The average wholesale price of these vials is $1.25 ($0.025/mcg) and $1.84 ($0.0184/mcg) per vial respectively. The purpose of this medication use evaluation was to quantify the cost related to fentanyl waste based on dispensed vial size and to assess the accuracy of fentanyl waste documentation by analyzing any discrepancies between fentanyl dispensed from the automated dispensing cabinets (ADC), documented doses administered, and recorded waste in the ADC.

This was a retrospective, randomized, single-center analysis of 50 adult patients treated at a large academic medical center ED, who received injectable fentanyl in both trauma and non-trauma settings. Two arms were analyzed for patients receiving fentanyl using 50mcg vials (July-August 2025) versus 100mcg vials (July-August 2024), representing separate periods when each vial size was available due to shortages. Data collected included the number of fentanyl vials (and corresponding total mcg) dispensed per patient, total fentanyl administered, and documented waste. A cost analysis compared anticipated waste between vial sizes and accuracy of waste documentation versus administered doses in the medication administration record. Data was evaluated using the Shapiro-Wilk test, Chi-square, and/or Wilcoxon rank sum test. A P-value ≤ 0.05 was considered statistically significant.

Patients receiving fentanyl 50mcg/1mL vials (N=25) were compared to those who received fentanyl 100 mcg/2mL vials (N=25). The mean total fentanyl dose administered was 53mcg versus 54mcg, respectively. The median amount of expected waste was 25mcg in the 50mcg vial arm versus 50mcg in the 100mcg vial arm. The mean fentanyl waste cost per patient was $1.025 for 50 mcg vials versus $1.582 for 100mcg vials with a calculated 54% decrease. Discrepancies in expected versus documented waste occurred in six patients (24%) in the 50mcg vial arm and five patients (20%) in the 100mcg vial arm (p= 0.733).

In conclusion, although 50mcg fentanyl vials cost more per mcg, when accounting for waste, 100 mcg vials result in higher overall cost. Of note, discrepancies in waste documentation were observed in both arms.