One size does not fit all-evolution of opioid agonist treatments in a naturalistic setting over 23 years

Methadone remains the mainstay of OAT, being prescribed to two-thirds of patients. Following its approval, the proportion of HAT increased rapidly and is now constant at 12.16% [95% confidence interval (CI) = 11.15-13.17]. The initial increase of proportions of buprenorphine or slow-release oral morphine (SROM) following their approval for OAT was slower. While in 2014 both medications had a proportion of 10.2% and 10.3%, respectively, our model predicts a further increase of SROM to 19.9% in 2018, with a ceiling level of 25.19% (21.40-28.98%) thereafter. SROM patients display characteristics similar to those treated with methadone; buprenorphine patients show the highest social integration; and HAT patients are the most homogeneous group, with highest mean age, most widespread injecting experience and lowest social integration. Conclusions: Based on data from Zurich, Switzerland from 1992 to 2015, there is no evidence for an excessive demand for a single medication in a naturalistic and liberal opioid agonist treatment setting. Rather, the specific patient characteristics associated with each medication underline the need for diversified treatment options for opioid dependence.