OUT-OF-HOSPITAL MEDICATIONSTORAGETEMPERATURES: A REVIEWOF THE LITERATUREAND DIRECTIONSFOR THE FUTURE

Emergency care drugs' chemical stability after eight weeks' deployment in the prehospital setting

Temperature conditions vary in emergency service vehicles, which may pose a risk to the integrity of the drugs on board, possibly rendering them ineffective and increasing morbidity and mortality in patients.

Aim

This study assessed the stability of four emergency care drugs (adrenaline, etomidate, ketamine, and rocuronium) after eight weeks of deployment in the prehospital context.

Methods

The study adopted a longitudinal quantitative design to evaluate the chemical stability of emergency care drugs. The study was conducted at four emergency medical service bases in Ballito, Durban and Pietermaritzburg, South Africa. The primary outcome was the relative reduction in drug concentration from the labelled concentration after four and eight weeks. High-performance liquid chromatography-mass spectrometry (HPLC-MS) analysed samples to determine the concentration of active ingredients in the drug samples.

Results

HPLC analysis was done on 176 samples. The ambient temperature ranged from 18.7 to 44 °C in the first four weeks, averaging 26.8 °C ± 3.0. At 4 and 8 weeks, Adrenaline decreased 24.93 % and 22.73 %, respectively. Etomidate's control had 3.06 mg/ml, not the 2 mg/ml on the bottle. After 4 and 8 weeks, the samples had 3.10 and 3.15 mg/ml active components, respectively. Ketamine degraded over 30 % after four weeks but not beyond that. The Ketamine package states 10 mg/ml. However, we found 17.46 mg/ml. Rocuronium was 6.45 mg/ml in the control, although the manufacturer specified 10 mg/ml. At four weeks, the concentration was 6.70 mg/ml; at eight weeks, 6.56.

Conclusion

This study suggests that adrenaline and ketamine degrade by more than 20 % within four weeks of deployment in the prehospital field, whereas etomidate and rocuronium remain stable after eight weeks.

Expired Epinephrine Maintains Chemical Concentration and Sterility

OBJECTIVES

Epinephrine shortages affect nearly all American emergency medical services (EMS) systems. Utilization of expired epinephrine could mitigate this situation in daily EMS operations. Concerns about using expired medications include sterility, potency, and potential harmful chemical decay byproducts. There are no cross-platform analyses of sterility and chemical purity of multiple samples of expired parenteral epinephrine. We hypothesized that epinephrine injections will remain sterile and will retain their active ingredient's content for more than 30 months past expiration.

METHODS

Six parenteral epinephrine prefilled syringes, 1 mg/10 mL, with an expiration date of January 1, 2012 had been stored in the climate controlled setting of a hospital inpatient pharmacy where they remained until they were taken for chemical or microbial analysis 30 months after expiration. An unexpired parenteral epinephrine prefilled syringe content was used as a control. Contents of three separate syringes with expired content from the same lot and one control underwent ultra-high pressure liquid chromatography-mass spectrometry (UHPLC-MS) and nuclear magnetic resonance (NMR) to determine epinephrine content and stability. In parallel, contents of another three expired epinephrine syringes were analyzed for sterility by plating on aerobic, anaerobic, and fungal media in a hospital microbiology laboratory. The aerobic plates were checked for growth in 3 days, the anaerobic in 5 days, and the fungal in 28 days.

RESULTS

UHPLC-MS and NMR showed that content of epinephrine present in the original sample remained unchanged compared to the control. There was no statistical difference in the UHPLC-MS and NMR signal amplitudes between the control and the expired samples. No chemical degradation byproducts were detected using NMR. There was no growth of any bacteria or fungus.

CONCLUSION

Recurrent epinephrine shortages impact EMS and hospital operations in the United States. Individual administrators may be hesitant to authorize use of expired pharmaceuticals due to perceived potential complications or fear of litigation. This study shows that the original parenteral epinephrine remains sterile and detectably pure more than 2.5 years after expiration. Further study of the sterility and chemical integrity of expired medications that had been subjected to the conditions of EMS vehicles may be a future research endeavor based on the aforementioned paradigm.

Hot and Cold Drugs: National Park Service Medication Stability at the Extremes of Temperature

STUDY OBJECTIVE

National Park Service (NPS) Parkmedics provide medical care in austere environments. The objective of this study was to evaluate the stability of specific medications used by Parkmedics at extremes of temperatures likely to be faced in the field.

METHODS

This is a bench research study conducted in the laboratory setting over a 4-week period. Parenteral medications were separated into 4 temperature exposure groups: A) 45°C (hot); B) -20°C (cold); C) hot then cold temperatures alternating weekly; and D) cold then hot temperatures alternating weekly. At study start and the end of each week, three aliquots from each group were sampled to determine the remaining drug concentration through liquid chromatography-quadrupole time-of-flight mass spectrometry (Agilent LC 1260- QTOF/MS 6550). Quantitative analysis was done using Agilent MassHunter Quantitative Analysis software. The mean drug concentration from triplicate aliquots was expressed as percentage of its baseline concentration to monitor the drug's stability during storage.

RESULTS

Eight medications were analyzed (atropine, diphenhydramine, fentanyl, hydromorphone, midazolam, morphine, naloxone, ondansetron). Hydromorphone, morphine, and ondansetron showed the greatest stability, at above 90% of original concentration in all study arms. Diphenhydramine, fentanyl and midazolam showed heat independent degradation, degrading the same way regardless of heat exposure. By the end of the study period, 51-56% midazolam remained in all groups. Atropine and naloxone showed heat dependent degradation, degrading more when exposed to heat. Atropine had the most degradation, being undetectable after 4 weeks of heat exposure.

CONCLUSIONS

We recommend that EMS providers replace atropine, naloxone, diphenhydramine, fentanyl, and midazolam frequently if they are practicing in low call volume or high-temperature environments. Further studies will be needed to determine if re-dosing midazolam, naloxone, and atropine is the appropriate clinical strategy in this setting if adequate clinical effect is not reached with a single dose.