Heroin is actually diacetylmorphine or diamorphine. It is a pain medication, changed to illegal status by politicians. It is less potent than Fentanyl. It should be class two. But the black market sale will continue because doctors are afraid to give pain medication to those who need it and are afraid to treat addicts. Oh, I forgot. They are afraid of going to jail for treating addicts! It is illegal to give medical care to "those people"! We let law enforcement take care of addicts, instead of physicians!

One statistic of interest. Up to 160,000 people a year are hospitalized and an estimated 16,000 die each year as a result of the gastrointestinal hemorrhage from NSAIDS (aspirin, ibuprofen, naproxen, etc.) In addition to that, there are a number thought to, now, be dying from heart attack, from the NSAIDS, as well. Compare that to the estimated 5500 who died from unintentional and intentional drug overdose!. The most deaths reported recently was attributed to hospital mistakes. 100,000 each year! That probably included those who die from the complications of acetaminophen and NSAIDS, as well. It is easier for the government to label that as a mistake. (Especially since they are going to start denying payment to those hospitals where the complications and mistakes occur.) But is clear that it is a very small percentage that die from the "abused" drugs compared to those legally used by hospitals and the public.

The NIH might have the information you seek. I found a lot of information one day when I was searching for drug related and overdose deaths. Information is available, but may not have the detail you are looking for.