Opioids are medicines made from the opium poppy or created in a laboratory. They block pain messages between the brain and spinal cord and the body. Opioids can be used to reduce some types of pain, such as acute pain and chronic cancer pain.
Learn more about:
- Working out the dose
- Opioids commonly used for moderate to severe pain
- Side effects of opioids
- Signs of withdrawal
- Common questions about opioids
There are different types of opioids and they come in varying strengths. The type you have depends on what kind of pain you have, how much pain you are in, and other factors such as how well your kidney and liver work, and whether you can take oral (by mouth) medicines. You can only have opioids by prescription from your doctor.
Codeine is an opioid that used to be commonly used for mild to moderate cancer pain. It is now only available by prescription and not often used.
Sometimes using opioids can cause more pain. This is called opioid-induced hyperalgesia. It happens because taking opioids for a long time makes specific nerves and the brain more sensitive to pain.
I was impressed the anaesthetist rang me in hospital the day after surgery to see how I was going and to check if the pain medicines were okay.Beth
Working out the dose
As people respond differently to opioids, the dose is worked out for each person based on their pain level.
It’s common to start at a low dose and build up gradually to a dose that controls your pain. Sometimes this can be done more quickly in hospital or under strict medical supervision. Some people do not respond to opioids.
Opioids commonly used for moderate to severe pain
You may be prescribed a combination of slow release and immediate release drugs. You may have immediate release to deal with breakthrough pain.
Slow release (long-acting) opioids
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Immediate release (short-acting) opioids
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Side effects of opioids
Opioids can affect people in different ways, but you may have some of the following common side effects:
Constipation – Taking opioids regularly can cause difficulty passing bowel motions (constipation). Opioids slow down the muscle contractions that move food through your colon, which can cause hard faeces (stools or poo). To keep stools soft, your treatment team will suggest you take a laxative at the same time as the opioid medicines. You may also be given a stool softener. Drinking 6–8 glasses of water a day, eating a high-fibre diet and getting some exercise can all help manage constipation, but this may be difficult if you’re not feeling well.
Feeling sick (nausea) – This usually improves when you get used to the dose, or can be relieved with other medicines. Sometimes you may need to try a different opioid.
Drowsiness – Feeling sleepy is typical when you first start taking opioids, but usually improves once you are used to the dose. Tell your doctor or nurse if you continue to feel drowsy as you may need to adjust the dose or change medicines. Alcohol can make drowsiness worse and is best avoided. Opioids can affect your ability to drive – learn more if you have concerns about driving.
Dry mouth – Opioids can reduce the amount of saliva in your mouth, which can cause tooth decay or other problems. Chewing gum or drinking plenty of liquids can help. Visit your dentist regularly to check your teeth and gums.
Tiredness – Your body may feel physically tired, so you may need to ask family or friends to help you with household tasks or your other responsibilities. Research shows that stretching or a short walk helps you maintain a level of independence and can give you some energy.
Itchy skin – If you have itchy skin, sometimes it may feel so irritated that it is painful. A moisturiser may help, or ask your doctor if there is an anti-itch medicine or a different opioid you can try.
Poor appetite – You may not feel like eating. Small, frequent meals or snacks and supplement drinks may help. If the loss of appetite is ongoing, see a dietitian for further suggestions.
Breathing problems – Opioids can slow your breathing. This usually improves as your body gets used to the dose. To help your body adapt to how opioids affect your breathing, you will usually start on a low dose and gradually increase the amount. Your doctor may advise you not to drink alcohol or take sleeping tablets while you are on opioids.
Hallucinations (seeing or hearing things that aren’t there) – This is rare. It is important to tell your doctor immediately if this occurs.
Signs of withdrawal
If you stop taking opioids suddenly, you will usually have withdrawal symptoms or a withdrawal response. This is because your body has become used to the dose (physical dependence). Withdrawal symptoms may include agitation; nausea; abdominal cramping; diarrhoea; heart palpitations and sweating.
To avoid withdrawal symptoms, your doctor will reduce your dose gradually to allow your body to adjust to the change in medicine. Don’t reduce your dose or stop taking opioids without talking to your doctor first. They will develop a plan to gradually reduce the dose.
Your health care team will closely monitor you while you’re using opioids. Let them know about any side effects you have. They will change the medicine if necessary.
Podcast: Managing Cancer Pain
Dr Tim Hucker, Pain Medicine Specialist, Peter MacCallum Cancer Centre, VIC; Dr Keiron Bradley, Palliative Care Consultant, Bethesda Health Care, WA; A/Prof Anne Burke, Co-Director Psychology, Central Adelaide Local Health Network, President, Australian Pain Society, Statewide Chronic Pain Clinical Network, SA, School of Psychology, The University of Adelaide, SA; Tumelo Dube, Accredited Pain Physiotherapist, Michael J Cousins Pain Management and Research Centre, Royal North Shore Hospital, NSW; Prof Paul Glare, Chair in Pain Medicine, Palliative Medicine Specialist, Pain Management Research Institute, The University of Sydney, NSW; Andrew Greig, Consumer; Annette Lindley, Consumer; Prof Melanie Lovell, Palliative Care Specialist HammondCare, Sydney Medical School and The University of Technology Sydney, NSW; Caitriona Nienaber, 13 11 20 Consultant, Cancer Council WA; Melanie Proper, Pain Management Specialist Nurse Practitioner, Royal Brisbane and Women’s Hospital, QLD; Dr Alison White, Palliative Medicine Specialist and Director of Hospice and Palliative Care Services, St John of God Health Care, WA.
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