Tramadol dispensing patterns and trends in Canada, 2007-2016.

Tramadol and "strong opioids" showed similar (bifurcated) use trends, with initial increases and subsequent inflections, yet reductions in dispensing occurred earlier for tramadol than for "strong opioids" (the latter occurring following with recent interventions). Distinct from experiences with differential opioid control regimes elsewhere, there is no evidence that tramadol figured as a "substitution" drug for increasingly restricted "strong opioids" in Canada.