BACKGROUND:
There are no published studies that report on fentanyl and ketamine compatibility in dextrose 5% solution as commonly practiced in hospital settings.

METHODS:
This study assessed the compatibility of fentanyl and ketamine after their reconstitution in dextrose 5% under ambient temperature and humidity conditions in a hospital setting. Each sample of fentanyl and ketamine was prepared in triplicate by adding dextrose 5% to a prefilled syringe until final concentrations of 9.8 µg mL⁻¹ for fentanyl and 192 µg mL⁻¹ for ketamine were achieved. The solutions were stored in syringes at an ambient temperature ranging 26-28°C either under a mixture of daylight and ambient lighting. 

RESULTS:
The solutions were clear and no physical changes were seen. The pH of fentanyl and ketamine decreased dramatically after 72 hours. 

 

Full text on source: https://www.ncbi.nlm.nih.gov/pubmed/29982991