Degradation of benzodiazepines after 120 days of EMS deployment.
Publication/Presentation Date
1-1-2014
Abstract
INTRODUCTION: EMS treatment of status epilepticus improves outcomes, but the benzodiazepine best suited for EMS use is unclear, given potential high environmental temperature exposures.
OBJECTIVE: To describe the degradation of diazepam, lorazepam, and midazolam as a function of temperature exposure and time over 120 days of storage on active EMS units.
METHODS: Study boxes containing vials of diazepam, lorazepam, and midazolam were distributed to 4 active EMS units in each of 2 EMS systems in the southwestern United States during May-August 2011. The boxes logged temperature every minute and were stored in EMS units per local agency policy. Two vials of each drug were removed from each box at 30-day intervals and underwent high-performance liquid chromatography to determine drug concentration. Concentration was analyzed as mean (and 95%CI) percent of initial labeled concentration as a function of time and mean kinetic temperature (MKT).
RESULTS: 192 samples were collected (2 samples of each drug from each of 4 units per city at 4 time-points). After 120 days, the mean relative concentration (95%CI) of diazepam was 97.0% (95.7-98.2%) and of midazolam was 99.0% (97.7-100.2%). Lorazepam experienced modest degradation by 60 days (95.6% [91.6-99.5%]) and substantial degradation at 90 days (90.3% [85.2-95.4%]) and 120 days (86.5% [80.7-92.3%]). Mean MKT was 31.6°C (95%CI 27.1-36.1). Increasing MKT was associated with greater degradation of lorazepam, but not midazolam or diazepam.
CONCLUSIONS: Midazolam and diazepam experienced minimal degradation throughout 120 days of EMS deployment in high-heat environments. Lorazepam experienced significant degradation over 120 days and appeared especially sensitive to higher MKT exposure.
Volume
18
Issue
3
First Page
368
Last Page
374
ISSN
1545-0066
Published In/Presented At
McMullan, J. T., Jones, E., Barnhart, B., Denninghoff, K., Spaite, D., Zaleski, E., Silbergleit, R., & Neurological Emergencies Treatment Trials investigators (2014). Degradation of benzodiazepines after 120 days of EMS deployment. Prehospital emergency care, 18(3), 368–374. https://doi.org/10.3109/10903127.2013.869642
Disciplines
Business Administration, Management, and Operations | Health and Medical Administration | Management Sciences and Quantitative Methods
PubMedID
24548058
Department(s)
Administration and Leadership
Document Type
Article