As noted in the previous post the drug abuse and drug morbidity surge that we experience is not with the traditional illegal drugs, like heroin and cocaine, but with prescription drugs.
By far, the drug category that outpaces all others in terms of volume of people ending up in emergency departments (see the slides below) or dead (the topic of later posts) are legally prescribed opioid drugs. Examples of these drugs are oxycodone, OxyContin, hydrocodone (Vicodin, Norco), and codeine.
As you will see below, the number of emergency department visits related to legal opioids since 2004 has almost tripled. In just five years.
Also notice that emergency department visits related to heroin are stable for the same period.

legal vs illegal opioids, national
Denver shows by and large a steeper growth rate (more than 300% growth in five years) but with a leveling of the data from 2008 — 2009.

All data is from the DAWN (Drug Abuse Warning Network) at https://dawninfo.samhsa.gov/ and are lifted from my presentation, “Prescription Drug Abuse: The Hidden Epidemic”