Opioid Medicines

Patient Experience

  • Reference Number: HEY1216/2021
  • Departments: Pain Medicine
  • Last Updated: 16 April 2021


This leaflet has been produced to give you help and support in using your opioid medicines safely.  Please keep it in a safe place.

Patients, family, friends and carers can play an important role in the safe use of these medications and in reducing the risk of harm.  Please share this information with them.

What are opioid medicines?

Opioids are a type of medicine that help to relieve pain.  They are very effective over short periods of time to relieve moderate to severe pain.  Opioids provide pain relief by acting on areas of the brain and spinal cord to block the transmission of pain signals.  They are considered to be the strongest pain relieving medication available and are used to treat pain after surgery, serious injury and cancer.  Opioid drugs can help manage some but not all types of chronic pain.

Examples of opioids include Codeine (including Co-Codamol), Tramadol, Fentanyl, Morphine and Oxycodone.

These medicines come in many different forms, such as injections, tablets, capsules, liquids and patches.

What are the risks with opioids?

Opioids have a serious risk of addiction and/or dependence, especially with long-term use.  The person prescribing an opioid or pharmacist or qualified health care professional (such as a pharmacy technician or a nurse) should explain how long it is safe for you to take your medicine for.

The most common side-effects of opioid medications include the following:

  • Nausea
  • Vomiting
  • Constipation
  • Itching
  • Drowsiness

For further information on using opioids safely and a full list of possible side effects please refer to the patient information leaflet that came with your medicine and keep it handy.

Opioid medicines can cause some problems when you take them for a long time.  These problems include:

  • Constipation
  • Weight gain
  • Difficulty breathing at night
  • Increased levels of pain
  • Irregular periods
  • Itching
  • Lack of sex drive
  • Reduced ability to fight infection
  • Reduced fertility
  • Erectile dysfunction in men

How can I take my opioid medicine safely?

 Only take the medicine as directed.
  • DO NOT increase the dose or take an extra dose
  • DO NOT take opioid medicines if you are pregnant without health professional advice
  • DO NOT alter your dose to more than you have been prescribed, this may cause overdose
  • DO NOT take any other medicines that contain opioids to “top up” your pain relief

(If you take modified release opioid with immediate release opioid, please ensure that you follow the dose and guidance instructions on your medications to avoid taking too much opioid which could lead to overdose).

Please talk to your doctor or to a pharmacist first if you are thinking of altering the dose of your opioids, or if you have any questions about your opioid medicine or side effects.  There may be alternative treatments which you could discuss with your doctor or pharmacist.

DO NOT ALLOW OTHERS to take any opioid medicines prescribed for you.  Your medicine has been prescribed for you by your doctor and can be very dangerous if taken by other people – it could cause a fatal overdose.


Can I drive when I am taking opioids?

In 2015 the law on drugs and driving changed, stating that if your driving is impaired for any reason, including taking prescribed medications, it is illegal to drive.

All opioid medicines have the potential to impair driving.  You are responsible for making sure you are safe on each occasion that you drive. The law in the UK allows you to drive if you are taking prescribed opioid medicines in accordance with the instructions, however


How do I know if I am becoming addicted or dependent?

Will my body get used to opioid medicines?

Opioids can become less effective with time (this is called tolerance) meaning your body has got used to the pain-relieving effect of the medicine.  You can also become dependent on opioid medicine (dependence).  This means that if you stop taking the drug suddenly or lower the dose too quickly, you can get symptoms of withdrawal which can include the following:

  • Tiredness
  • Diarrhoea
  • Aching muscles
  • Sweating
  • Runny nose
  • Stomach cramps

What about addiction to opioids?

Addiction can happen gradually.  It can make you feel that you are no longer in control of how much medicine you need to take or how often you need to take it.  You might feel that you need to carry on taking your medicine, even when it doesn’t help to relieve your pain.

Talk to your doctor if your pain is becoming difficult to manage as your body may not be sensing its pain-relieving effect.  This is referred to as “opioid tolerance” and could be an early warning sign that you may be at risk of becoming addicted to opioid medications.

Signs that you may be addicted to opioids include:

  • Craving for the medicine
  • Feeling that you need to take more medicine than prescribed or as instructed on the medicine packaging, even if it is causing bad effects on your overall health
  • Feeling that you need to take additional medicines containing opioids or other pain relief medicines to achieve the same relief
  • Experiencing withdrawal side effects when you stop taking the medicine suddenly (see list below)
  • Taking opioid medicines for reasons other than pain relief

If you notice some or all of the above signs, please talk to your doctor or pharmacist for advice and support.

How can I safely stop taking my opioid medication?

If you have been taking your opioid medicine for a long time, do not stop taking it suddenly because this may cause unpleasant withdrawal side effects.  It is important to get the right help and support when you are ready to stop taking your medicine.

If you have taken opioids for less than two weeks, you should be able to stop these medications as soon as your prescribed course of medicines runs out, if not sooner.

Talk to your doctor, nurse or pharmacist.  They will be able to help you come off your opioid medicine slowly to reduce the unpleasant withdrawal side effects.  Safely coming off your opioids can take a long time.  Every person is different.  Take any unused opioids back to the pharmacist for safe disposal.

Babies born to women who took opioids during pregnancy may need to be carefully monitored for withdrawal effects after their birth.  Talk to your doctor or midwife if you are worried.

Withdrawal side effects may include a combination of the following:
  • Shivers
  • Sweating
  • Body aches
  • Diarrhoea
  • Widespread pain
  • Increased pain
  • Difficulty sleeping
  • Nausea and vomiting
  • Irritability and agitation

If you experience any of the above symptoms, then please talk to the person who prescribed your medicine or your doctor or pharmacist.

What may happen if I take too much opioid medicine?

Taking too much opioid medicine, whether intentional or not, is called an overdose.  This can be very serious and may cause death.

Some of the signs that someone is experiencing an overdose included:

  • Confusion or hallucination
  • Slurred speech
  • Lips or fingernails are blue or purple
  • Poor coordination or balance
  • Unresponsive or unconscious
  • Heavy or unusual snoring
  • Difficulty breathing or no breathing
  • Very small pupils in the eyes

You, your family, friends and carers should know and recognize these signs so that they can take immediate action.

If you think that you or someone else has taken too much opioid medication, DIAL 999 IMMEDIATELY FOR HELP

Useful information:


Medicines and Healthcare Products Regulatory Agency – Opioid Medicines and the Risk of Addiction (2020)

Opioids Aware 2016 Faculty of Pain Medicine www.fpm.ac.uk/faculty-of-pain-medicine/opioids-aware

If you experience side effects to your opioid medicines you can report these directly to the Medicines and Healthcare products Regulatory Agency on the Yellow Card website, via the free apps (‘Yellow Card Scheme’ in the Google Play Store or ‘Yellow Card – MHRA’ in the Apple App Store), or by phoning the free phoneline (0800 731 6789).

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