Methadone :- 6-dimethylamino-4,4-diphenyl-3-hep-tanone, C21H27NO

               (CH3)2N-CH-CH3     
             ___       |
            /   \      |
           /  _  \     |
          /  / \  \____C___CO___CH2CH3
          \  \_/  /    |
           \     /     |
            \___/      |___      
                       /   \
                      /  _  \
                     /  / \  \
                     \  \_/  /
                      \     /
                       \___/ 

Methadone is a white crystaline solid with a melting point of 232oC, and has a bitter taste. It is considered useful in treating heroin addiction as it takes about a month before you get addicted to methadone. So you can perscribe it during the period the addict is suffering from withdrawal symptoms, without the patient becoming dependent on the methadone. Well that's the theory.....