You should never do Yohimbine & Disassociatives (DXM, PCP, Ketamine, Nitrous, etc.) on the same day as each other. Could cause Olney's Lesions (brain damage).
Dentists use it, so it has to be somewhat safe, but the deaths are all from people that had gas masks strapped on and passed out or people that took them then drove off a road or something.
Weekly use is probably a recipe for brain damage. Keep it to 1-2 times monthly TOPS kidz.