We don't allow drug testing discussion, we have an entire forum database you can read through, year after year of archived threads, reports, experiences with all things re: drug testing, and the forum has been closed for new posting but everything people ask here has already been answered anyways and the answer to all drug testing questions if we have them, will be in the Drug Testing Questions forum.
I don't know why you're using OTC anything in doses that would make you concerned a false positive for opioids on a 5 panel UA, OTC highs are extremely stupid and the amount you have to take to feel "effects" that how anyone enjoys, is beyond my understanding, but by the time you're "high" you're also usually causing damage to your organs and psychiatric health... Dextromethorphan, is the right isomer of a synthetic opioid: Levomethorphan, which is indeed an opioid, and there's that to consider.... Anyways, look in the correct forum for information about this please.