Actually, it can pop you hot for Methadone
. This actually happened to me when I was living in a sober house a while back. There was always a very faint ghost line on methadone, but I wasn't really worried about ('cause ghost lines still constitute a pass), but then a time came when it was a full on fail. I was really surprised, and started looking through a book of false positives. I was looking for benadryl
or DPH, but it wasn't in there. Then I found Methadone, and it said "antihistamines" can trigger it. As Funky said, it was fine, because I just had them send it to the lab. I also think it's hard to make this happen though, if you're not a heavy user, and are not as neglectful of nutrition and general health as I was. Every time after that, I would just drink a glass or water and pee before the test, this took care of it completely. Like I said though, I had a bad diet; didn't drink much water at all, and I was taking the stuff quite a bit. So, I would bet you don't have to worry about it, never hurts to err on the side of caution though.
P.S. you don't have to drink a shit load of water to pass - which is good, since this would be a dilute, and an automatic fail. When I passed, there was still color in my pee.