Morphine and other opioids for pain

‘Opioids’ are a group of medicines used to treat and manage moderate to severe pain. The most widely-known opioid is morphine. Others include oxycodone, fentanyl and codeine. Opioids work well for many types of pain and are most commonly used after surgery and for cancer pain.


1 When are opioids used?

If pain is severe and has not responded to regular paracetamol, a weak opioid, usually codeine, can be added. Codeine is similar to morphine but is about one tenth as strong. A good combination is codeine and paracetamol together in one tablet called ‘cocodamol’. If this does not help the pain, you may be offered a stronger opioid such as morphine.

Opioids can be given at any stage during an illness. If the pain improves, the dose may be reduced and sometimes stopped but if the pain is due to cancer, it is likely that the opioid will be needed long-term.

2 How effective are opioids?

Opioids are strong pain-killers and usually relieve pain effectively. Other medicines and treatments can be used at the same time as opioids because pain may have more than one cause, for example if the pain is being caused by damage to a nerve, opioids may not be so effective and other medicines may be needed in addition or instead. Most people will have good pain relief with opioids once the dose is right for them and for their pain.

3 How to take strong opioids

There are several ways to take opioids and they are available as tablets, liquid medicines and injections. Patches which release opioid medication into the body through the skin are another option.

Immediate-release preparations (I/R)

These usually start to work within 20 to 30 minutes and their effects last for about 4 hours. They may be used to work out the right dose for you as it can be increased or decreased quickly.

I/R opioids can also be used ‘when necessary’ to fit with the pain. If the pain is there all the time, I/R products will need to be taken several times a day.

• I/R opioids include Oramorph, Sevredol tablets and oxycodone capsules (and also Abstral tablets, which are different and last for a shorter period).

Modified-release preparations (M/R)

These also start to work within about 30 minutes but they are designed to be effective for 12 hours or longer, depending on the preparation. It is important to take M/R opioids at regular times – perhaps 9am and 9pm to ensure the pain is controlled evenly.

• M/R opioids include MST tablets, Zomorph capsules and oxycodone M/R tablets.


Patches which work through the skin last for several days – some three or four days and some for seven days. These can be very convenient when pain stays at the same level.

• Patches include fentanyl, Durogesic, MatrifenBu-Trans and Transtec.


Injections work within about 15 minutes and the effects can last for about four hours, depending on the opioid. If you have problems taking medicines by mouth then you may be offered opioids by injection or by using a syringe pump which gives the opioid continuously over 24 hours.

• Injections include morphine, diamorphineoxycodone and alfentanil.

In most cases, you will be offered an opioid that works ‘around the clock’ and given another I/R opioid to take for extra pain relief when required. You will be given instructions for how and when to take these different opioids.

Keep an up to date list of your opioids (and other medicines) to show other doctors or healthcare professionals

Whenever you start to take opioids, especially at first, your nurse or doctor will check with you regularly so that dose is found that is rightfor you and your pain.

4 Side effects

All medicines have side effects and with opioids the most common ones are:

Nausea (feeling sick) This usually wears off after a couple of days as your body gets used to the opioid

Constipation This is an unavoidable side effect of opioids and means that you will be offered a laxative to take whilst you are taking opioids.

Drowsiness Many people find they are drowsy and find it difficult to concentrate when they start taking opioids or when their dose increases. As with other medicines, you should avoid manual tasks that need concentration if you feel like this. You may find that in time, this effect wears off and you should be able to return to your normal activities.


It is important to note that a new offence came into effect in March 2015, which said it is an offence to drive with high levels of drugs such as opioids in the body. However, if you feel confident that your ability to drive is not impaired and are taking your opioids as directed, then you would not be breaking the law.

It is recommended that you keep some documentation with you (e.g. the leaflet that comes with the medicine) to show that you are taking the opioid as prescribed for you.

Further information is available at You may also want to check the position with your insurance company.

You should not stop taking opioids without speaking to your doctor or nurse and should not take more than the dose you have been advised to take but if you are experiencing a serious or new side effect or have accidentally taken too much then you should contact them quickly. If you have serious side effects such as difficulty breathing, feeling jerky and jumpy and very rarely, becoming unconscious, dial 999 and keep your medicine containers with you to show what you have been taking.


Common questions

Will I get addicted to opioids?
Although many people worry about this, when opioids are taken for pain they do not cause addiction. Many people stay on the same dose for a long time but it is also common for the dose to
increase gradually. If the pain improves, the opioid can be reduced.

Do opioids shorten life?
Research shows that they do not.

Will the opioids get less effective if my pain gets worse?
There is no maximum dose for opioids so the dose can be slowly and carefully increased if your pain increases.

Can I go on holiday if I am taking opioids?
It is possible to travel to most places in the world with opioids although the rules are different in some countries. Ask for advice from your doctor, nurse or pharmacist.

6 Safe storage and disposal

Opioids are ‘controlled drugs’ so there are additional safety measures with prescribing and supplying them. You or a representative may be asked for identification when collecting a
prescription. Store all your medicines in a safe place, out of the reach of children and return any unwanted medicines to your local community pharmacy. If you come in as a patient to the hospice, we may ask your family to take any unwanted medicines, including opioids, to a pharmacy for safe disposal.


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