"Methadone is the most commonly prescribed substitution medication, received by up to two-thirds of substitution clients, while buprenorphine is prescribed to most of the remaining clients (about 20%), and is the principal substitution medication in six countries (Figure 3.7). About 6% of all substitution treatments in Europe rely on the prescription of other substances, such as slow-release morphine or diacetylmorphine (heroin).
"An estimated 734,000 opioid users received substitution treatment in Europe in 2012. This figure is relatively stable when compared with 2011 (726,000), but higher than the 630,000 estimate for 2007 (Figure 3.8). In 2012, five countries reported increases of more than 25 % in client numbers compared to the previous year’s estimate. The highest percentage increase was noted in Turkey (250 %), followed by Greece (45%) and Latvia (28%). The percentage increases in these three countries, however, occurred in the context of relatively low base numbers. In contrast, during the same period, Romania (?30 %) reported the largest percentage decrease in estimated client numbers."

Source

European Monitoring Centre on Drugs and Drug Addiction, "European Drug Report 2014: Trends and Developments" (Lisbon, Portugal: EMCDDA, 2014), p. 58.
http://www.emcdda.europa.eu/e…
http://www.emcdda.europa.eu/p…
http://www.emcdda.europa.eu/a…