THE METABOLIC FATE OF THE OPTICAL ISOMERS OF METHADONE

The fate of the optical isomers of methadone was investigated in rats. Although the d - and l -isomers differ greatly in their pharmacological actions, only minor differences were noted in the distribution and excretion of each compound. The rate of metabolism of each isomer by liver slices was practically identical and was affected to the same extent by various enzyme inhibitors. The optimal pH for the reaction was also the same for both isomers. It would appear that both isomers have certain metabolic pathways in common.