"i received dilaudid through iv while in er for kidney pain. the pain relief was very fast and effective. however, i had noticeable side effects - that disorienting whoosh effect mentioned by another commenter, severe dizziness, nausea and blurred vision. when admissions asked me to sign paperwork i had significant trouble raising my arms and holding the pen, but i was able to sign my name with a great deal of concentration. getting out of bed was very difficult when they asked for a urine sample. i needed quite a bit of assistance from the nurse to walk across the hall. all i wanted to do was lie very still and minimize the dizziness. it took about 8 hours for this effect to go away."