@holland13 Welcome to Mayo Clinic Connect! I’m glad you found us. I, also, had a problem with Rituximab the first time I got it. I was monitored for a while in the infusion center and then they sent me to the ER. No long term affects, but I was taken off the drug. A few years went by and I kept telling the doctors that Rituxan helped me so much that I had to try again. So, I tried again with a more dilute solution and Benadryl prior. The infusion usually takes 1 hour, but, for me, it takes almost 3 hours. I feel fine after! Talk to your doctor and try again! Suggest that you do the desensitization protocol as in the wonderful article which @gently sent.
And try to relax! Have a good book or some music with you!
Will you talk to your doctor? I know you can do it!!