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Morphine for pain relief

MST, Oramorph, Zomorph

This medicine is an opioid painkiller. There is a serious risk of addiction when taking this medicine, especially if used long-term. The Medicines and Healthcare products Regulatory Agency (MHRA) has issued new guidance for people prescribed an opioid painkiller. If you have any questions or concerns about taking opioids safely please speak with your doctor or a pharmacist.

Morphine is prescribed to treat severe pain.

You may be prescribed morphine to take regularly, or only when it is needed for pain relief. Make sure you know which is right for you.

The most common side-effects are constipation, drowsiness and feeling sick (nausea). Your doctor will be able to prescribe medicines to take with morphine to help with some of these side-effects.

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About morphine

Type of medicine

Strong opioid painkiller

Used for

Pain relief

Also called

Actimorph®; Morphgesic®; MST Continus®; MXL®; Oramorph®; Sevredol®; Zomorph®

Available as

Tablets, slow-release tablets and capsules, oral liquid medicine, sachets, melt-in-the-mouth 'orodispersible' tablets, and injection

Strong opioids are medicines used to treat severe or long-term (chronic) pain. Although there are many types of strong opioids (sometimes called opiates), morphine is the most commonly used. It works on your nervous system and brain to reduce the amount of pain you feel.

Morphine can be taken as a liquid by mouth, as quick-acting tablets, or as slow-release tablets and capsules. It is also available as an injection. Morphine is commonly given by injection in hospitals following surgical operations. Oral preparations of morphine come with various different brand names, and not all brands are absorbed by your body in the same way. Once you have started taking one brand, you should continue to take the same brand unless your doctor tells you to switch to another.

Before taking morphine

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking morphine, it is important that your doctor knows:

  • If you are pregnant, trying for a baby or breastfeeding.

  • If you have liver or kidney problems.

  • If you have prostate problems or any difficulties passing urine.

  • If you have a heart condition or heart rhythm problems.

  • If you have any breathing problems, such as asthma or chronic obstructive pulmonary disease (COPD).

  • If you have been told you have low blood pressure (hypotension).

  • If you have any problems with your thyroid, pancreas, or adrenal glands.

  • If you have epilepsy.

  • If you have a problem with your bile duct.

  • If you have been constipated for more than a week or have an inflammatory bowel problem.

  • If you have a condition causing muscle weakness, called myasthenia gravis.

  • If you have recently had a severe head injury.

  • If you have ever been dependent on drugs or alcohol.

  • If you have ever had an allergic reaction to a medicine.

  • If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.

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How to take morphine

  • Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The manufacturer's leaflet will give you more information about the specific brand of morphine you have been prescribed, and a full list of the side-effects which you may experience from taking it.

  • Take morphine exactly as your doctor tells you to. Depending on the reason you are taking it, your doctor may advise that you take regular doses or take it only when you need it for pain relief. Make sure you know which is right for you. Your dose will be printed on the label of the pack to remind you.

  • Slow-release tablets of morphine should be swallowed whole with a drink of water - do not break or crush the tablets. Slow-release capsules can generally either be swallowed whole, or alternatively, opened and the contents sprinkled on to soft food such as yoghurt. Check the label on your pack for further information about how you should take your tablets/capsules.

  • There are several different strengths of morphine tablets and capsules so each time you collect a prescription check to make sure it is the strength you are expecting.

  • You can take morphine before or after food.

  • If you forget to take a dose, take it as soon as you remember and then continue as before. If it is nearly time for your next dose, leave out the forgotten dose and take the next dose when it is due. Do not take two doses together to make up for a forgotten dose.

Getting the most from your treatment

  • Ask your doctor for advice before drinking alcohol while you are on this medicine. Your doctor may recommend you do not drink alcohol while you are on morphine because it increases the possibility of side-effects such as feeling dizzy and sleepy.

  • If you are a driver, please be aware that morphine is likely to affect your reactions and ability to drive. It is an offence to drive while your reactions are impaired. Even if your driving ability is not impaired, should you drive, you are advised to carry with you some evidence that the medicine has been prescribed for you - a repeat prescription form or a patient information leaflet from the pack is generally considered suitable.

  • If you are having an operation or dental treatment, tell the person carrying out the treatment that you are taking morphine as a painkiller.

  • If you buy any medicines, check with a pharmacist that they are suitable for you to take with morphine. Many other medicines have similar side-effects to morphine, and taking them together will increase the risk of these.

  • If you are planning a trip abroad, you are advised to carry a letter with you from your doctor to explain that you have been prescribed morphine. This is because morphine is classed as a 'controlled drug' and is subject to certain restrictions.

  • Do not take morphine for longer than you have been advised by your doctor. This is because repeatedly using morphine may lead to your body becoming dependent on it. When you then stop taking it, it will cause withdrawal symptoms such as restlessness and irritability. If you are concerned about this, discuss it with your doctor or pharmacist.

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Can morphine cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with morphine. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.

Common morphine side-effects

What can I do if I experience this?

Feeling sick (nausea) or being sick (vomiting)

Stick to simple meals - avoid rich or spicy foods. Also, try taking your doses after food, as this may help

Shallow breathing

Let your doctor know about this

Feeling dizzy, sleepy or drowsy

If this happens, do not drive and do not use tools or machines. Do not drink alcohol


Eat a well-balanced diet and drink plenty of water each day. If this continues to be a problem, speak with your doctor

Dry mouth

Try chewing sugar-free gum or sucking sugar-free sweets

Other common side-effects include: feeling confused or disorientated, itching, sweating, mood changes, disturbed sleep, headache, difficulties passing urine, flushing, and rash

If any of these become troublesome, speak with your doctor

Important: people taking opioid medicines, and their family and friends, should be aware of the risk of accidental overdose and know when to seek medical help. The risk is higher if you also take other medicines that make you feel drowsy. Signs you have taken too much medicine include:

  • Feeling very sleepy or dizzy.

  • Feeling sick (nausea) or being sick (vomiting).

  • Breathing difficulties.

  • Loss of consciousness.

If you have taken more morphine than you should or someone else accidentally swallows your medication, call for an ambulance and tell them the name of your medicine.

If you experience any other symptoms which you think may be due to this medicine, speak with your doctor or pharmacist.

How to store morphine

  • Keep all medicines out of the reach and sight of children.

  • Store in a cool, dry place, away from direct heat and light.

Important information about all medicines

Important information about all medicines

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital. Take the container with you, even if it is empty.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about this medicine ask your pharmacist.

Report side effects to a medicine or vaccine

If you experience side effects, you can report them online through the Yellow Card website.

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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