Resistance to topical / injectable analgesic

My questions extends beyond the upcoming core biopsy of my breast. I am more concerned about the procedure than the results at the moment. Why? I have undergone a whole list of procedures over the years in which a topical, then injectable analgesic was used. No matter how many times this happens the med. staff downplays/doesn't take my history seriously. They'll say "I've been doing this x# years and its a simple procedure". First the topical doesn't numb me so I feel the shot so bad I cry out. Then the procedures often cause me to scream then faint because the analgesic didn't work. Here's my question. I know no-one is out to get me but how do I explain things so staff will treat me as an individual with an unfortunate resistance to analgesics etc. as generally administered? These situations are traumatic for me.