Opioids are drugs that work to relieve pain by binding to the body’s opioid receptors. Opioid drugs are separated into three different types based on their composition. Natural opioids are derived from the resin of Papaver somniferum, the opium poppy, while semisynthetic opioids are synthesized from the poppy’s resin or from a natural opioid. Synthetic opioids are manufactured compounds that mimic the action of opioids. Most opioid drugs work as general pain relievers, but some are better at targeting specific types of pain.
Morphine and codeine are natural opioids. Morphine is a powerful pain-relieving drug and is often used for cancer pain. It is also used to treat severe, chronic pain and as a short-term pain reliever for intense pain. Codeine is weaker than morphine and is used to treat moderate to moderately severe pain.
Semisynthetic opioids include hydrocodone, oxycodone, and benzylmorphine. Oxycodone works well for patients with combined nerve and bone pain. It is also highly addictive and has a propensity for abuse when not taken as directed. The semisynthetic group of opioids also includes hydromorphone, oxymorphone, and buprenorphine. Buprenorphine is used both to treat moderate pain and to treat opioid addiction.
Synthetic opoid drugs do not contain opioids, nor are they synthesized from other opioid drugs. Their chemical structure resembles that of other opioids, and they work in the same manner. This group includes methadone, fentanyl, and dextropropoxyphene. Methadone targets nerve pain. It is also used in the treatment of heroin addiction.
Tramadol and tapentadol are opioid drugs that are in a separate class. They do not contain opioids, are not synthesized from opioids, and are not chemically similar to other drugs in the opioid class. They do, however, bind to the body’s opioid receptors and as such are considered opioids. Tramadol was originally developed as a way to treat pain without using addictive opioid formulations, but it was found to be as addictive as traditional opioids in some patients.
There are several routes of administration for opioid drugs, although not all opioids are available in all forms. Most can be taken orally in pill form, and some are available as an injectable liquid. There are opioid-based lollipops and lozenges for patients who cannot swallow pills. Patients who need a constant delivery of pain medication can use opioid patches. The patches deliver the opioids directly to a specific site as well as absorb into the bloodstream, providing both direct pain relief and a constant supply of pain medication.