Cancer drugs A to Z list
Morphine is a type of painkiller. You can only get it on prescription from your doctor. You have it for moderate to severe pain.
It is also known as:
Morphgesic SR
MXL
Zomorph
MST Continus
Sevredol
Oramorph
Actimorph
Sometimes you might have morphine as an injection. This might be:
if you can't swallow
if you feel sick
during or after a cancer procedure or surgery
You usually have injections under the skin (subcutaneous injection) into the stomach, thigh or top of your arm.
You might have stinging or a dull ache for a short time after this type of injection but they don't usually hurt much. The skin in the area may go red and itchy for a while.
Some people have morphine under the skin continuously through a small needle connected to a pump called a syringe driver. It gives a continuous small amount of morphine.
Your nurse will change the syringe driver every 24 or 48 hours. This way of having morphine is helpful for people who find it difficult to swallow.
You have the injection into a muscle, usually into your buttock or upper thigh.
You can have morphine injected into your bloodstream.
This might be through a thin short tube (a cannula) that goes into a vein in your arm. Or through a long plastic tube that goes into a large vein in your chest. You may have one of these if you are having cancer drugs such as chemotherapy. This tube can be a:
central line
PICC line
Portacath
Some people have morphine through a pump called a patient controlled analgesia (PCA) machine. The pump is attached to the cannula or tube into your chest. You press a button and the pump gives you a small amount of morphine. The pump then locks for several minutes. When the pump unlocks you can press it again. This means you can control the painkillers yourself.
Find out more about having medicines into a vein
Side effects can vary from person to person. They also depend on what other treatment you are having.
Your doctor, nurse, or pharmacist will go through the possible side effects. They will monitor you closely during treatment and check how you are at your appointments. Contact your advice line as soon as possible if:
you have severe side effects
your side effects aren’t getting any better
your side effects are getting worse
We haven't listed all the side effects here. Talk to your healthcare team if you have any new symptoms that you think might be a side effect of your treatment.
Remember it is very unlikely that you will have all of these side effects, but you might have some of them at the same time.
How often side effects to morphine can happen depends on how you have it. Some are more common if you have them as an injection.
These side effects happen in more than 10 in 100 people (more than 10%). You might have one or more of them. They include:
This means your body is not getting the oxygen it needs. It is potentially life threatening. Tell your doctor or nurse immediately if you are breathing slowly or not very deeply.
Slow, shallow breathing is more common if you have morphine as an injection. But it can happen with all types of morphine.
is easier to sort out if you treat it early. Drink plenty and eat as much fresh fruit and vegetables as you can. Try to take gentle exercise, such as walking. Tell your healthcare team if you think you are constipated. They can give you a laxative if needed.
Feeling or being sick is usually well controlled with anti sickness medicines. It might help to avoid fatty or fried foods, eat small meals and snacks and take regular sips of water. Relaxation techniques might also help.
It is important to take anti sickness medicines as prescribed even if you don’t feel sick. It is easier to prevent sickness rather than treat it once it has started.
You may notice that the black part in the middle of your eyes (pupils) look smaller than normal. This is less common if you have long acting morphine or morphine as an injection.
This includes feeling extremely happy or feeing unhappy and agitated. Less often you might have mood swings, feel less active than normal or you might feel really active.
Some people can have difficulty processing or expressing their thoughts.
Confusion, sleepiness or extreme lack of energy (lethargy) and seeing or hearing things that aren't there (hallucinations) can be a possible side effect of this treatment. If you have any of these, it is important to tell your doctor or nurse straight away.
These are more common if you have morphine as an injection.
You sweat to keep your body cool. Morphine can make you sweat more than needed. Doctors call this hyperhidrosis. Wearing loose fitting clothing made from natural materials such as cotton can help improve your symptoms.
You might feel itchy when you take morphine.
Less often you might get raised itchy bumps on your skin. This can happen if you are having an allergic reaction to the morphine.
Tell your doctor or nurse straight away if you have any of these symptoms. They can give you some medicine to help.
These side effects happen in between 1 and 10 out of every 100 people (between 1 and 10%). You might have one or more of them. They include:
difficulty sleeping
dizziness or
headaches
sudden jerking of the body due to muscle contractions
extreme tiredness and weakness
loss of appetite
generally feeling unwell
tummy (abdominal) pain
taste changes
dry mouth
fits (seizures) – tell your doctor straight away if this happens
indigestion - symptoms include heartburn, bloating and burping
not being able to pee or pass enough urine – especially if you have other problems that make peeing difficult
high pressure around your brain - symptoms include a headache, being sick and eye sight changes. You should see a doctor straight away if you have these symptoms
being very sensitive to pain and other sensations such as touch, heat and pressure
less interest in sex
problems
eye problems - including blurred vision or involuntary eye movements
tightening of the muscles that line the airway (bronchospasm)
fluid on the lungs making it difficult to breathe
a slow or fast heart beat
low blood pressure – you might feel dizzy, lightheaded or faint. This might happen when you stand up
decreased bowel movement which can cause abdominal pain
sudden swelling, commonly in the face – this may be due to an allergic reaction. Tell your doctor or nurse straight away if you get any sudden swelling
redness (flushing) of the face
These side effects happen in fewer than 1 in 100 people (fewer than 1%). You might have one or more of them. They include:
an allergic reaction that can cause a rash, shortness of breath, redness or swelling of the face and dizziness - some allergic reactions can be life threatening. Alert your nurse if you notice any of these symptoms
stiff muscles
tingling or numbness in the skin
fainting
high blood pressure
swelling from a build up of fluid in the arms or legs
spasms in the
Cancer drugs can interact with medicines, herbal products, and some food and drinks. We are unable to list all the possible interactions that may happen. An example is grapefruit or grapefruit juice which can increase the side effects of certain drugs.
Tell your healthcare team about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies. Also let them know about any other medical conditions or allergies you may have.
It is not known whether this treatment affects in people. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.
This treatment may harm a baby developing in your womb. It is important not to become pregnant while you are having treatment. Talk to your doctor or nurse about effective contraception before starting treatment.
Don’t breastfeed during this treatment because the drug may come through into your breast milk.
If you are having tests or treatment for anything else, always mention your cancer treatment. For example, if you are visiting your dentist.
People taking morphine for weeks or months can develop a physical dependence. This causes withdrawal symptoms if morphine is stopped.
Your doctor or nurse will advise you how to reduce the morphine dose gradually if necessary. Don't stop taking morphine suddenly.
Some people can also develop a psychological dependence (addiction) to morphine. This may be more likely in people who have problems with alcohol or drug use.
Last reviewed: 25 Jul 2025
Next review due: 25 Jul 2028
There are different causes and types of cancer pain, and many different ways of managing and treating it.
Whatever painkillers you have to treat cancer pain, it helps to know more about what you're taking and any possible side effects.
What happens after surgery depends on the type of anaesthetic, operation and how well you recover. You normally have a wound. And you may have some tubes and drains when you wake up.
Cancer drugs have side effects and these can vary from person to person. But there are things that you can do to help you cope.
Coping with cancer can be difficult. There is help and support available. Find out about the emotional, physical and practical effects of cancer and how to manage them.
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