Intravenous Drug Use of Opioids and HIV transmission: Opioids 101
Opioids are natural and synthetic derivatives of opium, a compound produced by the poppy plant. Opium and its derivatives have been used for their medicinal purposes for thousands of years in many different cultures. It is interesting to note that the body produces its own class of chemicals that work in the nervous system the same way the opioids work. Two compounds from opium are morphine and codeine. The compound “morphine” is named after the Greek God Morpheus, the God of dreams. Indeed, morphine and other opioids can produce a euphoric, dream-like state, that can be quite pleasurable. This sensation activates the reinforcement pathways in the brain which drive the desire to seek this experience again. Heroin is another opioid derived from morphine.
The opioid drugs have a number of medical uses. These compounds are useful for treating diarrhea. Opium tincture (Paregoric) has been used. The drugs diphenoxylate (a component of Lomotil) and loperamide (Imodium) are opioid-related compounds in over-the-counter anti-diarrhea meds. Opioids also have antitussive or a cough suppressive activity. Codeine is a very effective cough suppressant and it used to be used in over-the-counter cough suppressants. Dextromethorphan is an opioid-related drug used in many over-the-counter cough suppressants.
But one of the most important medical purposes of the opioid drugs is their use as analgesics. They are really the best drugs we have for moderate to severe pain. They are an extremely important class of drugs, but they are a double-edged sword. The opioids used in treating pain can also produce euphoria, which can activate the reward pathways in the brain that reinforce behaviors and can lead to abuse and addiction (see the previous article that describes the components of addiction). So one challenge in using opioids is to effectively manage pain without becoming addicted. For most people, this is not a problem. Most of us have taken opioids for dental procedures, a fracture or sprain, lower back pain, surgery and other medical problems. Our pain was controlled and we didn’t become addicted.
Another problem is that opioids are central nervous system depressants. They can suppress or slow down brain activity. This is very important because, at high doses, opioids can kill. This usually happens when opioids suppress the brain’s control of breathing after a person loses consciousness. So death from an opioid overdose usually occurs from respiratory depression. There are a number of opioid products used for treating pain which include morphine, Codeine (combined with Tylenol as Tylenol#3), Oxycodone (combined with