In the December 2017 issue of the Pain journal I read an excellent article about opioids by Jane Ballantyne and Mark Sullivan: "Discovery of endogenous opioid systems: what it has meant for the clinician’s understanding of pain and its treatment" (full article here). In the same issue there is also a commentary by Daniel Clauw: "Hijacking the endogenous opioid system to treat pain: who thought it would be so complicated?" (full article here). Both articles describe how opioid receptors in the human body are there to interact with chemicals made in the human body. This innate opioid system is important for many functions in the body (some examples include mood, metabolism) and social functions. Basically, a therapy with high dose opioids alters all these innate mechanisms. Another issues is that a high dose opioid therapy may interfere with other nonpharmacological therapies for pain that likely use the endogenous opioid system: exercise, acupuncture and mind body therapies.
Currently, the U.S. is going through an opioid epidemic and opioids are frequently discussed in the news. I think it is important to look at the bigger picture. Humankind has a long history with opioids. There are some theories that even Neanderthals used poppy seeds. A good timeline is presented here by PBS. There were even opium wars between the British Empire and China with the British Empire promoting opium trade. It is a fascinating read about the first opium war and then the second opium war. At that time people had all kind of ideas about how drugs work. A quote from the first article above: "during the many centuries that opium and its derivatives were used for pain, the efficacy of opiates was often attributed to divine benevolence. Thomas Sydenham, the 17th-century “English Hippocrates,” wrote “Among the remedies which it has pleased Almighty God to give to man to relieve his sufferings, none is so universal and so efficacious as opium.” Sir William Osler called opium, “God’sOwn Medicine.”
Our last excessive use of opioids started in the lat 20 years with a significant increase in deaths. CDC estimates that from 1999 to 2015, more than 183,000 people have died in the U.S. from overdoses related to prescription opioids. This does not include the deaths related to illegal opioids. More statistics are available on the CDC website. In March 2016 CDC came up with guidelines about opioid prescription: long version and short version. Basically, the recommendation is to be very cautious when prescribing more than 50 mg Morphine equivalents daily and have a very good reason to prescribe more than 90 mg Morphine equivalents daily. Most people nowadays are prescribed hydrocodone and oxycodone as outpatient opioid medication. Hydrocodone dosage is equivalent to morphine dosage, so 10 mg hydrocodone is equivalent to 10 mg morphine. Oxycodone is one and a half time more potent than morphine, so 10 mg oxycodone is equivalent to 15 mg morphine. Oxycontin is the slow release version of oxycodone and the same conversion as for oxycodone applies.