Strong opioids

Information about taking opioids for patients and carers

Introduction to opioids

Opioids are ‘morphine-type’ medicines which have been used for many years to treat pain in a similar way to the body’s natural pain relievers. Low doses of opioids are also prescribed to help with breathlessness and cough.

Strong opioids, such as morphine or oxycodone, are used to relieve moderate to severe pain when weaker pain medicines, such as paracetamol or codeine, are not effective. They are used short term for pain after surgery, a heart attack or trauma when the dose is reduced as the pain eases. 

Opioids can also be used to manage pain or symptoms caused by cancer or long-term conditions such as heart failure, lung or liver disease. This can be done at different stages of disease alongside other treatments and does not necessarily mean that someone is close to the end of their life.

Commonly used opioids include codeine, dihydrocodeine, tramadol, morphine, oxycodone, fentanyl and buprenorphine. They are available in different forms including tablets, capsules, liquid, skin patches and injections. Opioids can be taken with other medicines that work in different ways to improve pain control including paracetamol, anti-inflammatory drugs or NSAIDs (such as ibuprofen or naproxen), and drugs for nerve pain (such as amitriptyline and pregabalin). Codeine and dihydrocodeine can also be combined with paracetamol in one tablet (such as Co-dydramol or Co-Codamol). 

Pain often prevents people being able to carry on with their lives and move around. Taking opioids can help to reduce pain and improve ability to do everyday tasks such as getting dressed or walking. It is important to realise that it may not be possible to take the pain away completely. Pain and other symptoms may need to be managed in alternative ways as well as or instead of medicines.

How to take opioids for pain

There is no standard dose of an opioid as the amount needed to control pain varies from person to person. Opioids are usually started at a low dose and gradually increased up (titrated) to the correct dose. Most people are initially prescribed morphine but if it does not suit them then a different opioid, e.g. oxycodone, may be used.

Strong opioids are usually prescribed in a combination of two forms: a long-acting (slow or modified release, MR) form taken regularly to control ‘background’ pain and a short-acting (immediate release, IR) form to be used on an as required or ‘rescue’ basis. Depending on the type of pain, you may be prescribed immediate or slow release or both.

Shor Acting Opioids

Immediate release (IR)

Long Acting Opioids

Slow or modified release (MR)

e.g. Oramorph, Sevredol

e.g. Zomorph, MST

Usually liquid or tablet either regularly* or as required

May be given as intramuscular, intravenous or subcutaneous injection in certain situations

Usually tablets or capsules taken twice a day (every 12 hours)

Skin patches may also be used


Start to act within 20 - 30 mins and usually last for 3 - 4 hours Release opioid into your blood stream gradually over a longer period (hours to days)
Used as needed for sudden, intense or flares of pain (also called ‘breakthrough pain’ Taken on a regular basis at the same time each day )e.g. 08:00 and 20:00 

* Short acting opioids may initially be prescribed regularly to safely titrate the correct dose and then converted to a long-acting form. Your specialist will advise you have often to take them.

Skin (transdermal or TD) patches such as Fentanyl or Buprenorphine can be useful for people who are unable or prefer not to take medicines by mouth or in people with kidney problems. They are applied like a plaster and release the opioid medicine slowly through the skin over a few days. This means there may not be an immediate effect on symptoms when a patch is first started.

Patches are usually changed once or twice a week.

Common side effects

  • Constipation affects nearly all people taking opioids and may require you to take regular laxatives, e.g. 1-2 senna tablets at night. Your doctor or nurse can advise you how to manage this.
  • Nausea or sickness can occur when you first start taking opioids but this usually improves after a few days. An anti-sickness medicine can be prescribed to take if needed.
  • Dry mouth can be helped by frequent sips of drinks (at room temperature), sugar free chewing gum and good mouth care. Artificial saliva products (including gels and mouth sprays) are available and can be prescribed by your doctor.
  • Drowsiness usually passes within a few days of starting opioids or after a dose increase. Opioids may help you to recover your normal sleep pattern, but they should not make you drowsy in the daytime.

Other possible side effects

  • persistent drowsiness or loss of concentration
  • bad dreams
  • hallucinations
  • confusion
  • muscle twitching
  • itching
  • difficulty passing urine.

If the above side effects occur, please seek prompt review by a doctor or nurse as it may be necessary to reduce your dose or switch to a different opioid

Follow-up and further prescriptions

If you are taking opioids or other types of pain medicines for longer than a few weeks, you will need regular monitoring by your GP or specialist team to ensure they are still helpful and not causing problems. You can also get advice from your pharmacist.

You may be given an initial supply of medicines in hospital but repeat prescriptions are usually issued by your GP.


What should I do if I am still in pain?

You can try taking an additional dose of ‘rescue’ opioid if this was prescribed by your GP or specialist team otherwise please seek medical advice as soon as possible. It is advised not to stop opioids suddenly as you may get withdrawal effects (see below).

What if I forget or miss a dose?

You should take it as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and take your medication as normal. 

Do not take two doses together.

Can I drive while taking opioids?

It is not safe to drive when you first start taking opioids and after a dose change because you may be drowsy or unable to concentrate. UK law allows you to drive after taking opioids if you have been prescribed them and followed advice on how to take them by a healthcare professional and are fit to drive. You are responsible for making sure you are fit to drive.

For more information:

Can I drink alcohol?

Alcohol should be avoided as it increases the side effects of opioids and may make you very drowsy. This is even more important if you are driving or using machinery and when you first start taking opioids.

Will my body get used to strong opioids?

Opioids can become less effective with time as your body gets used to the effect of the medicine (tolerance). Most people develop a physical dependence with prolonged use. If you stop taking opioids suddenly, or lower the dose too quickly, you can get unpleasant withdrawal symptoms. These include tiredness, sweating, runny nose, stomach cramps, diarrhoea, cramps, body aches, anxiety and worsening pain.

If these symptoms occur, please seek prompt medical advice.

Will I get addicted?

There is a small but increased risk of addiction (psychological dependence) in people who take opioids for longer periods of time. For example, you may feel you need to carry on taking your opioids even when they don’t help relieve your pain or you may feel you are no longer in control of how much you need to take.

For more information:

Please talk to your GP or specialist team if your pain or symptoms are becoming difficult to manage.

How should I store my opioids?

You should keep them in the original packaging, in a cool, dry place.

All medicines should only be taken by the person they are prescribed for (not friends and family) and kept out of the reach of children and pets.

Please return any unused opioids to your local pharmacy for safe disposal.

Can I travel abroad with opioids?

Check the laws of the country you are travelling to as not all will allow you to enter with opioids. All opioid medicines need to be carried in hand luggage and you will need a letter from your prescriber to confirm your details.

For more information:

Useful information and guidance

NICE guidance on strong opioids

NHS medicines

Opioid medicines and the risk of addiction

Faculty of Pain Medicine

Patient information leaflets:

Opioids Aware:

Contact details for specialist team

Named Consultant:


Named Specialist Nurse:


GP/Community Contact:


Pharmacy Patient Helpline (Mon–Fri, 9am–5pm) 020 3315 2704


For emergency advice out of hours please call 111.


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