Usually in Germany, levomethadone, methadone, buprenorphine and, in special exceptional cases, codeine or dihydrocodeine may be prescribed as "substitute drugs". Since 21st July 2009, narcotic law provisions also permit the use of diamorphine for the management of a severe opiate dependence in special institutions and under strict requirements (e.g. not less than five years history of severe opiate dependence, two failed opiate addiction therapies, patient has completed their 23rd year of life). This treatment can offer individuals with an extremely severe opiate addiction who often can no longer be reached with other substitution treatments a way out of their addiction. The regulation was based on a pilot project in seven German cities that abundantly proved the superiority of diamorphine treatment for this group of extremely dependent individuals (such as improvement of health status, reduction of or abstinence from hard drugs use, enhanced social integration, housing and employment situation).