How much promethazine will fuck me up

It’s all I got rn to hold me over, 6.25mg promethazine and 15mg dxm per 5ml. The most promethazine I’ve taken before was probably like 45mg, but that was with codeine. How much promethazine can I safely take to get me fucked up? I’m 158lbs and 5’10 if that matters