Ethylmorphine (also known as codethyline, Dionine, and ethyl morphine) is a drug in the class of both opiates (representing a minor synthetic change from morphine) and opioids (being effective in the CNS's opioid reception system). Its effects in humans mainly stem from its metabolic conversion to morphine. Chemically, it is a morphine molecule with a -25 group substituted for the aromatic 3-group. Therefore the closest chemical relative of ethylmorphine is codeine, also known as methylmorphine. Ethylmorphine also has a hydromorphone analogue (ethyldihydromorphinone or 3-ethoxy-7,8-dihydro-morphin-6-one), and a dihydromorphine analogue known as ethyldihydromorphine, although none of them appears to be commercially distributed at the current time. In most countries and internationally ethylmorphine and codeine are regulated much the same way.