a biologically active preparation for human or veterinary use for the selective blockade of opioid binding sites of the brain responsible for respiratory depression containing in a biologically active quantity the codeinone derivative of general formula or its salt r 1 means amino -, hydroxyl -, -- nh - phenyl or -- nh -- co -- nh 2 groups , r 2 means a hydrogen atom or a hydroxyl group . the invention also covers a process for selective blocking the opioid binding sites of the brain responsible for respiratory depression by administering to a patient in need of an analgetic a preparation containing a codeinone derivative of general formula or its salt preferably three times per day in doses of 2 . 5 - 5 mg . a preferred feature of the inventions is an analgetic composition containing a codeinone derivative of general formula and in a mass ratio of 1 : 2 - 3 morphine of the formula or an other , biologically equipotent agonist type opiate or opioid compound and optionally inert , pharmaceutically acceptable accompanying materials .