I'm going to shorten the story up for time's sake. I picked up 2 bottles of Robitussin Maximum Strength and a 48 pack of Benadryl. Around 10:30pm, I downed 1 1/2 bottles of the robo and downed 24 benadryl within 1 minute. Now I had done this before, but with 27 benadryl and had no problem really.
Anyway, the last thing I remember was sitting in my chair watching tv. Apparently my mother came upstairs, something she never does, and I was acting very strange (really?). They called an ambulance and I ended up in the emergency room. They made me drink charcoal, which I don't remember, but I puked it up a while later. This was scary because I didn't remember drinking it, all this black stuff, I was scared shitless. They also put a catheder (sp?) in which was quite unnecessary and two IV's.
They came back with the results of a urine test with 'positive for PCP and Opiates'. I had explained earlier that I took benadryl and robo, but they also thought I took pcp and opiates on top of it. I got out the next morning and it took a few days to clear my name of the PCP and Opiates.
In summation, the false-positive is true. Ending up in an emergency room with IV's, a catheder, a belly full of charcoal, false-positives for pcp and opiates, angry parents and a head full of DXM and DPH can make for one scary trip.