Figure 1: High morphine can show up with some hydromorphone, but generally hydro will break to hydro and oxy to oxy. Codeine can go to morphine and hydrocodone (not a metabolite of other opiates). Heroin breaks down to morphine and 6MAM. Codones can break to morhpones but not backwards. Hydrocodone can go to hydrocodol (= dihydrocodeine) and hydromorphone. Hydromorphone can go to hydromorphol (same for oxy but separate).