How Opioid Painkillers Work, Why They’re Addictive, and How to Avoid Dependence
A study has found that one in 10 people who use opioid painkillers are dependent on them, while one in eight are at risk of abusing prescription opioids. How worried should you be?
What are the most common opioid painkillers and how do they work?
Prescription drugs containing opioids are designed to be used for short-term acute pain relief, such as after surgery, and to help patients near the end of their lives. They include tramadol, codeine, oxycodone, morphine, methadone, and fentanyl. Guidelines from the National Institute for Health and Care Excellence states that they should not be used to treat chronic primary pain in the long term. Opioid drugs travel through the blood and attach to opioid receptors in our brains. This blocks the sensation of pain, increases pleasure, and can reduce the anxiety and stress that pain causes.
According to the NHS, side effects of opioid painkillers include excessive sleepiness and confusion and constipation. They make breathing shallower and slower and do not respond to increased oxygen demands. They have negative effects on the immune system. And they also affect people’s hormones and how they work to keep the body and mind in balance. Some people may become more sensitive to pain (hyperalgesia) as a result of taking opioid medications.
Why are they addictive?
Dr Lars Williams, a consultant anaesthetist and pain specialist at NHS Greater Glasgow & Clyde pain service, explains in an upcoming issue of Pain Matters magazine that we all produce our own opioids (endorphins) which act on the opioid receptors found throughout the body’s pain system. But because opioid painkillers are much stronger than the opioids our bodies make, the first time we take a morphine family of drugs the effect is strong. Each subsequent time the effect is less strong as the opioid receptors become less sensitive, so you need larger and larger doses. This leads to physical dependence which causes more pain and withdrawal symptoms when doses are reduced or stopped.
What are the signs of dependency?
They vary from patient to patient, but include taking increasingly larger doses as the body finds the current dosage insufficient to control pain; cravings for the next dose; withdrawal symptoms when the prescription runs out; and the inability to cut back. Withdrawal symptoms can include heart palpitations, panic attacks, nausea, aches, sweating, and shaking.
I have just had surgery and have been prescribed codeine. How do I prevent dependency?
Your doctor should explain how to take your medicine safely. Read the instructions on the packaging and do not exceed the stated dose or the length of time you take it. If you are still in pain, make an appointment with your GP to discuss how to manage your symptoms.
What should you do if you think you are too dependent on opioid prescriptions?
If you need support with challenges with prescribed medicines, talk to your GP or contact WithYou, a drug, alcohol and mental health charity. You can speak to a trained advisor for free and confidentially via their webchat service available at wearewithyou.org.uk.