Today was a rare day in my ED, we had an extra nurse. I was chosen to float. We do this when we can. The float nurse will help start IVs, pass meds and dc patients. Night was going fine. I look at my board and a dc pops up with an order of toradol IM and zofran SL. Since we have a policy of a 30 minute watch time after injections I figured I would knock out the meds for the nurse and get her dc paperwork ready during her watch time. So I draw up the 60 mg of toradol and head to the patient's room. I pull up the MAR and I see an hour before she had been given dilauded IM. I ask if she was still in pain (she came in for back pain) and she was. I see she is allergic to mobic so I ask her what her allergy is (said her stomach bled) and I ask her if she had had toradol before (she had). Well our system will flag an allergy so I knew when they order was put in for the toradol, it had to be over-rided. So I scan her bracelet, the med, give her the injection and leave the room to go get her paperwork ready. That's when it happens. I run into her nurse and let her know I gave the meds and I was getting her paperwork ready. She is upset. Well turns out she had put the order in on the wrong patient. She was trying to cancel the order as I was walking out of the patient's room. I felt like I was going to pass out. We go straight to the NP that was in assigned to the patient. Confirmed with the patient her "allergy" to mobic and we watched her for any reaction (there was none). We informed the charge nurse and wrote the incident report. My charge nurse was really good about it. He talked to me about his med error (I think to make me feel better, ha!) I am truly mortified though. I know I share equal blame in this because I could have always asked her before I went in to do it. I feel terrible that I could have hurt the patient and that I probably got my coworker in a lot of trouble with me. I feel like I won't (and maybe rightfully so) be trusted by my peers. At the end of the shift my coworker was really nice about it, but I still feel terrible. I know I've seen posts about med errors before, but I'm looking to see if anyone has had one similar to mine and can share how they got past it. Thanks in advance!