T.F.
Benedryl ASAP and stop the case study for your friend. Your health is not worth risking for her study.
I felt very weird for a couple of days while on vacation in FL this past July. I had just started an antibiotic that I had taken before. My gut instinct was to stop the antibiotic which I did. My hubby would not let me sleep until I saw the Dr for fear that I would not wake up.
My Dr. told me if I had continued taking this medication and gone to sleep, I could have died. YES, you can get an allergy even if you have used a certain product before.