The opioids are a class of medication that takes its name from the opium poppy, where opioids were originally derived. One of the main functions of opioids is to produce pain relief and they have been the mainstay of analgesia for thousands of years.
An opioid is a natural or synthetic chemical, similar to morphine. Opioids work by binding to opioid receptors in the central nervous system (brain and spinal cord) and our body produces its own natural opioids, called endorphins. Opioids reduce the nerve transmission to the brain and reduce feelings of pain and affect those brain areas controlling emotion. They are used to treat moderate to severe pain.
The body develops a physical dependence to opioids when they are taken for just a few weeks. There are other medications that produce physical dependence including anti-hypertensive and anti-epileptic medications and this term should be differentiated from addiction. However, opioid dependence can lead to withdrawal symptoms when the opioid is stopped so discontinuation should occur under doctor supervision.
The side effects of opioids can be strong, and potentially serious, including sedation, respiratory depression, constipation, and a sense of euphoria (profound wellbeing). Opioids such as morphine are well known for their addictive properties so need to be taken judiciously and responsibly. However, the rate of addiction amongst people taking opioids for chronic pain is unknown in Australia although the number of hospitalizations has risen with the increased prescription rate for strong opioids.
Not everyone taking opioids will get the desired pain relief to bring chronic pain to a tolerable level. Thus, doctors will generally prescribe opioid medication as a trial for a few weeks to see if there is pain relief that enables the person with pain to increase their capacity to complete more of the tasks of daily living. Managing opioid prescriptions long-term may also include signing an agreement to take the medication only as prescribed and urine tests can also be performed to ensure there is compliance with the medication.
Scientific research is now producing opioids to minimize the undesirable side-effects such as constipation and others are being reformulated so that they are difficult to misuse.
Other research is occurring in identifying opioid peptides which could hold promise for improving opioids for longer term therapeutic use while reducing the unwanted side-effects.
There are multiple forms of opioids used to treat pain.
These include "weak" opioids which can be often combined with other medications such as paracetomol. These include:
"Stronger" opioids (only available with a prescription) include:
Opioids are commonly used to treat chronic pain and may work well in combination with other medicines such as anti-epileptic and amitryptaline as well as non-medicinal therapies and can be effective as part of this holistic management process. Research shows that best practice pain management involves combining medication with greater "lifestyle" activities such as exercise and goal setting to re-engage with the important activities that make life worth living.