The Methadone Maintenance Program was the first Oral Substitution Therapy program that was started in Nepal  in the year 1994 AD at the mental hospital, which was phased out in 2002 AD due to various reasons.

The program was restarted inKathmanduat the TU Teaching hospital in 2007 AD, and currently, it has been again started at the mental hospital in 2011. Methadone is being dispensed to more than 100 clients per day on all days in a year. Besides that psychosocial counseling is also being provided to the clients under the guidance of Clinical Psychologist.