I recently received Compazine IVP, a flush then 50mgs of Benadryl IVP (very fast and undiluted). It was given through a Peripheral H/L. First, it burned like heck! Then, I had this feeling of "impending doom". Then all of a sudden, my heart rate went from about 85 BPM to an SVT rate of >200 BPM and then I turned pale, I became dizzy and started coughing. Then my BP went from 140/85 to 190/150 in a matter of minutes with an onset immediately after the Benadryl. I thought I was gonna die of a massive MI or stroke out or something!! Very scarey! Especially when you're a nurse and a patient and you start self diagnosing. I hope I never go through that ever again!