Questions about opioid painkillers?
Ask our specialist nurses on our Support Line any questions about opioids and side effects.
What's in the 'Pain and pancreatic cancer' information section?
- Managing pancreatic cancer pain
- What is pain and what causes it?
- Types of pancreatic cancer pain
- Who can help manage my pain?
- Painkillers for pancreatic cancer pain
- Non-steroidal anti-inflammatory drugs (NSAIDs) and paracetamol
- Opioid painkillers for pancreatic cancer
- Common concerns about opioid painkillers
- What if my pain relief isn’t working?
- Other types of pain relief for pancreatic cancer
- How does a nerve block treat pancreatic cancer pain?
- Dealing with pancreatic cancer pain
There are different types of opioid painkillers used to manage pancreatic cancer pain. These include weaker and stronger opioids.
Opioid painkillers may be taken in different ways, and have different side effects. You may take them with other types of pain relief. The type of painkiller you have will depend on what kind of pain you have, and your general health.
What are the different types of opioids used for pancreatic cancer?
Weaker opioids include codeine, dihydrocodeine and tramadol. Stronger opioids include morphine, oxycodone, fentanyl, buprenorphine and methadone.
Some stronger opioids are available in two forms:
- fast acting opioids, which are also called immediate release
- long acting opioids, which are also called slow or modified release.
What are fast acting opioids?
Fast acting opioids (immediate release) start to work after about 20 minutes and reach full effect after about an hour. This makes them good for treating breakthrough pain or sudden changes in pain.
You may start off with a fast acting opioid.
What are long acting opioids
You usually take a long acting opioid (modified release) twice a day to control background pain. These opioids take longer to have the full effect. So you must take them regularly at the same time of day for them to work properly.
Your doctor or nurse will work out the best dose for you that manages your pain with as few side effects as possible. The dose can be increased, so let your doctor or nurse know if you still have any pain.
“Take painkillers as soon as you experience any pain. Don’t feel you have to suffer in silence or that it’s better not to take them. Dealing with pain quickly and effectively will improve the quality of your life.”
What are the side effects of opioids?
Like all medicines, opioids can cause side effects. We explain the most common side effects here, but you may not get all or any of these. Some side effects settle down within a few days of starting a new drug. Others may last longer.
Speak to your doctor or nurse if you have any side effects. Your doctor may prescribe medicine to treat the side effects or change the dose of your painkillers. Or they may give you a different opioid drug or another type of pain relief.
Do not stop taking opioids without talking to your doctor first. Stopping opioids suddenly can make you very unwell.
Constipation
Opioids can cause constipation, which is when you find it harder to poo.
Your doctor or nurse may give you medicines, called laxatives, to prevent or treat constipation. If you are taking a stronger opioid like morphine, you may need to start taking a laxative straight away. You will need to take laxatives as long as you are using stronger opioids. It can also help to drink plenty of water and try to keep active, if you can.
Speak to your dietitian or nurse for any diet tips that might help with constipation.
“ We found that including things like prune juice or syrup of figs into his diet helped with constipation.”
Sickness and dry mouth
Opioids can make you feel and be sick (nausea and vomiting). This usually gets better after two to five days as your body gets used to your painkillers, but it can last longer for some people. Your doctor or nurse will give you medicine to prevent sickness. They may change the type of painkiller if your sickness continues.
You may also get a dry mouth. Drinking water, sucking ice cubes or chewing gum may help. There are also gels and sprays that can help. If you have white spots in your mouth or a white coating on your tongue, you may have an oral thrush infection. Your doctor can give you medicine to treat this.
Tiredness
Another common side effect of opioids is tiredness. You may also feel dizzy or have trouble concentrating. You may have this when you first start taking a new opioid, or when you change the dose. The tiredness will usually go away within a day or two as you get used to your painkillers.
Drinking alcohol can make tiredness worse. Tiredness and trouble concentrating can affect your driving.
Tiredness may not just be caused by your painkillers. The cancer and treatment can cause extreme tiredness (fatigue).
Other side effects
Other possible side effects include:
- mood changes or feeling confused
- having strange dreams
- itchy skin
- problems emptying your bladder completely
- muscle twitches or jerks.
It’s rare but sometimes people may also sense things that aren’t there (hallucinations).
Speak to your doctor or nurse if you have any of these side effects, especially if you have recently changed your painkiller. They may check your medicines, change the dose of your painkiller, or give you a different painkiller.
Speak to our nurses
Updated April 2025
To be reviewed April 2028