Opioids are generally used for pain that is hard to ignore or feels very severe. Moderate pain may be a pain score of 4–6 (out of 10), and moderate to severe pain may be a score of 6–10.
There are many different types of opioids, which are always prescribed by a doctor.
Some opioids, such as codeine, are used for moderate pain. Codeine relieves pain by being broken down in the body into morphine. However, some people cannot convert codeine, so they don’t get any pain relief from it. If taking Panadeine® or Panadeine® Forte feels like it has the same effect as paracetamol, inform your doctor. You may need other opioids.
Strong opioids, such as morphine, oxycodone, hydromorphone, methadone and fentanyl, are safe and effective for moderate to severe pain. These drugs are listed in the table opposite. Fentanyl, for example, is mainly used for severe pain that is fairly constant, or in lozenge form for rapid relief of breakthrough pain. Targin® is a combination of oxycodone and another drug, naloxone. Using naloxone eases constipation, a common side effect of opioids.
The dose of opioid is worked out for each person to match their pain level. You may start at a low dose and build up gradually until you reach the right dose.
Opioids can affect people in different ways. It can take a few days to adjust to taking strong pain medications. You may have some of the following side effects:
- Drowsiness – Feeling sleepy is typical, but this usually only lasts for a few days until the pain relief dose is stable. Tell your doctor or nurse if it lasts longer.
- 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. Rest is important, but it’s also beneficial to do some light exercise or activity, such as stretches or walking in the garden or to the letterbox. This helps you maintain a level of independence and can give you some energy.
- Feeling sick – This passes when you get used to the dosage or can be relieved with other medication.
- Constipation – Most people regularly taking opioid medications need a laxative. Drinking plenty of water, eating a high-fibre diet and getting some exercise also help reduce constipation.
- Itchy skin – If you have itchy skin, sometimes it may feel so irritating that it seems painful. Ask your doctor if there is an anti-itch medication available, or if you can try a different opioid for your pain.
- Dry mouth – Chewing gum or drinking plenty of liquids helps.
- Poor appetite – You may not feel like eating. Small, frequent meals or snacks and supplement drinks may help.
- Confusion or hallucinations – This is rare, so tell your doctor if it occurs.
Side effects can occur when you stop taking opioids suddenly too. These are sometimes called withdrawal symptoms or a withdrawal response.
To reduce the chance of side effects when you stop taking opioids, your doctor will reduce your dose gradually to allow
your body to adjust to the change in medication. It is important not to reduce your dose or stop taking opioids without talking to your doctor first.
Differing opinions about pain management
Families and friends sometimes have different opinions about pain relief. Your family members may feel anxious about you taking strong pain medication, or disagree with it (perhaps because they are worried that you will become addicted).
If this happens, have the medical staff talk to your family about the prescription, and explain why they have recommended a particular treatment for you.
Common questions about opioids
Most people have questions about taking opioid medications. Some common questions are answered on the following pages. Your pain specialist or nurse can also discuss any concerns you have.
If you are caring for someone with cancer pain, you may have some other specific questions about opioids.
Will I become addicted to opioids?
No – people taking morphine or other opioids to relieve pain do not become addicted. However, after some time, the body gets used to opioids and if they are stopped suddenly, you may get withdrawal symptoms. This is normal and is not the same as an addiction.
However, a person who has previously had a drug addiction problem may be at risk of addiction to opioids, if they are later used for cancer pain relief.
Using opioids regularly for pain relief is practical and not considered an addiction. Your doctor will monitor your dosage to maintain effective pain relief and avoid potential side effects.
Taking opioids for pain relief is different to an addiction. Someone with a drug addiction problem takes drugs to satisfy physical or emotional needs, despite the drugs causing harm.
Will I need to have injections?
Not necessarily. Strong pain relievers are usually given by mouth in either liquid or tablet form. If you’re vomiting, opioids can be given via the rectum as a suppository, by a small injection under the skin (subcutaneously), using a skin patch or in lozenge form.
Opioids can be injected into a vein for short-term pain relief, such as after surgery. This is called intravenous opioid
treatment and it is given in hospital.
Will the opioids still work if I get used to them?
Rarely, people who have used opioids for a long time may become tolerant to their original dose. Their doctor will need
to increase the dose to keep their pain under control.
Your dose of opioids may also be increased if your pain gets worse. There is no benefit in saving the pain control until the
pain is severe.
However, cancer treatment may make your pain better and you may end up needing less pain medication or even none. If your pain levels decrease or you no longer need opioids, your dose will be reduced gradually to avoid side effects that may occur if you were to stop taking medication suddenly.
Can I stop the medication at any time?
If your pain gets better, morphine and other opioids should be reduced slowly before stopping them completely. It is
important not to stop taking opioids suddenly because this can cause side effects, such as flu-like symptoms or nausea.
You should only reduce your dose or stop taking opioids in consultation with your health care team.
Can I drive while using opioids?
Doctors have a duty to advise patients not to drive if they are a risk to others. During the first days of treatment, you might be less alert, so driving is not advisable. Once the dose is stabilised, you may want to consider driving. Seek your doctor’s advice and keep the following in mind:
- Don’t drive if you’re tired, have been drinking alcohol, are taking other medication that makes you drowsy, or if road conditions are bad. Avoid driving at night or long distances.
- If you have a car accident while under the influence of a drug, your insurance company may not pay out a claim.
- Special rules and restrictions apply to people with brain tumours, including secondary brain cancer, or people who have had seizures.
What if I get breakthrough pain?
You might get a flare-up of pain even though you’re taking regular doses of medication. Breakthrough pain may last only a few seconds, several minutes or hours. It can occur if you’ve been more active than usual or you’ve strained yourself. Sometimes there seems to be no reason for the extra pain.
Your medical team can prescribe you medication for breakthrough pain. Slow-release opioids must not be taken for breakthrough pain.
You need to talk to your health care team who will advise you on how to cope with breakthrough pain. Usually it’s okay to take extra, or top-up, doses of a short-acting opioid (immediate release opioid), which will be prescribed in addition to your regular medication. The doses work fairly quickly, in about 30–40 minutes.
It is helpful to keep a record of how many extra doses you need so your doctor can monitor your overall pain management. If you find your pain increases with some activities, taking an extra dose of medication beforehand will allow you to enjoy that activity more.
The following drugs work on certain kinds of pain and might be prescribed with opioids to help you get the best pain relief. They are usually given by mouth or vein.
Some of the drugs take a few days to work, so opioids are used to control the pain in the meantime. If you are taking another drug, it may be possible to lower the dose of the opioids, reducing side effects without losing control of the pain.
This information was last reviewed in November 2013
This information has been reviewed by: Dr Melanie Lovell, Consultant Palliative Care Physician, Senior Lecturer, Sydney Medical School, University of Sydney, NSW; Prof Frances Boyle AM, Professor of Medical Oncology, Mater Hospital and University of Sydney, NSW; Prof Michael J Cousins AM, Professor & Head, Pain Management & Research Centre, Royal North Shore Hospital, NSW; Carol Kanowski, Clinical Nurse Consultant, North Queensland Persistent Pain Management Service, QLD; Brenda Kirkwood, Helpline Operator, Cancer Council QLD; A/Prof Odette Spruyt, Director, Pain and Palliative Care, Peter MacCallum Cancer Centre, VIC; and Sally White, Consumer.View our editoral policy