To solve the opioid crisis, stick to harm reduction?
No
To solve the problem eliminate prohibition. Legalize the sale of all now illicit drugs so accurately dosed, pure contaminant free substance can be bought at competitive prices. 
Require a course to be taken to understand the drug that people want to use, no different from driving cars or buying firearms. Moderate profits help pay for rehab. Criminals are put out of business, and policing costs drop.
Prohibition never did work in the past, and it isn't going to suddenly start working because of further ill planned "wars on drugs"