What if adults could just buy the drugs they need from licensed dispensaries?
If they need them for pain, fine.
If they want to get high, fine.
They're adults, after all. 
Governments worldwide have proven themselves utterly incompetent in addressing the negative health outcomes associated with prohibition.
How could the health outcomes of legalization possibly be any worse than the 2500+ deaths from street opiate/opioid overdoses in 2016? (And nevermind the awful state of many addicts who nonetheless didn't die...)
We now have decades of proof: prohibition is a failed model.
It creates and encourages violent black markets, costs us untold millions in law enforcement and first response expenses, and .. oh yeah .. hasn't done _a thing_ to reduce the rate of drug use or accessibility in North America or anywhere else not run by a homicidal dictator named Duterte.
We've had decades of this garbage. DECADES. 
Time to change course entirely.