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Date issued: May 2023

Review date: May 2025

Ref: C-431/LP/REI Inpatients/The safe use of opioid drugs v2

PDF:  The safe use of opioid drugs final May 2023 v2.pdf [pdf] 151KB

Key Messages

• Opioids are good analgesics (pain killers) for acute pain (short term pain) and for pain due to some cancers. There is little evidence that they are helpful for long term pain.

• Opioids should be taken in as low a dose as possible and for as short a time as possible after surgery.

How do opioids work?

Opioids provide pain relief by acting on areas in the brain and spinal cord to block pain signals. Opioids are the strongest painkillers available and are used to treat pain after surgery, serious injury (trauma) and cancer.

What are the different opioid drugs called?

Opioid drugs are usually called strong, intermediate and weak although this does not mean weaker opioid drugs are less effective for pain. The commonest strong opioid used in hospital is Oramorph (a trade name for liquid morphine). Other opioids include oxycodone (another strong opioid), tramadol (an intermediate opioid) and codeine (a weak opioid). It is not usual to take a strong opioid and a weak opioid at the same time. The advice below regarding Oramorph also applies to the other opioids.

What dose should I take?

The dose of Oramorph prescribed depends on several factors, including your age. In hospital it is usually prescribed as needed and you can ask for it every two hours. You should ask for Oramorph if your pain is moderate or severe on movement. When at home the dose of Oramorph and the time interval between doses will be different. It is important to take the dose prescribed for pain relief to be safe and effective.

What effect should opioids have on my pain?

It is not usual to get complete relief of pain from opioids.  Pain relief medicine should reduce your pain by at least one half.

How long will it take to work?

Oramorph usually works within 20 minutes and will last for around 4 hours. 

What are the possible side effects?

When you first start taking opioids you can get some side effects, which usually stop after a few days. These include:

• Feeling dizzy.

• Feeling sick (nausea).

• Being sick (vomiting).

• Feeling sleepy.

• Feeling confused.

• Being constipated.

Sometimes these side effects can go on for longer than a few days. Your healthcare team may give you some other medicines to help, such as anti-sickness tablets or laxatives. If you feel unsafe taking opioids, stop them and discuss with your GP. You cannot drive whilst taking opioids short term as your judgement may be impaired.

Can I take other painkillers with opioids?

It is usual to take other non-opioid pain relief medicines regularly. Opioids can be taken with these if needed, in addition. Medicines prescribed regularly include paracetamol and anti-inflammatories such as ibuprofen or naproxen.

Can I drink alcohol while I am taking opioid painkillers?

Alcohol and opioids both can cause sleepiness and poor concentration. If you are taking opioids, you should avoid alcohol in the post-surgical period.

How long should I take opioids for after surgery?

After surgery, you will be able to take opioids for the first few days to weeks provided they continue to be safe and effective. Your inpatient pain service will help to manage your use of opioids. Once you have gone home, you should take opioids for as short a period as possible.

Often, opioids are not required after leaving hospital. If you need them, you will be prescribed no more than 5 day’s supply of strong opioids to use as directed. As your pain decreases with time, stop the opioids first before stopping other regular painkillers (paracetamol and anti-inflammatory medicines).

Your pain should gradually reduce after you leave hospital. If it does not, it is important to discover why. If your pain gets suddenly worse within the first two weeks, this could be due to a surgical complication such as a wound infection. If it gradually worsens after 2 weeks, it may mean you are getting used to the opioids. Over time, opioids become less effective (called opioid tolerance). If this happens, you may have been taking them too long and reducing and stopping them is very important. Your General Practitioner (GP) can help with either of these problems.

If you feel you need strong opioids for more than five days, you will need to be reviewed by your GP. It is important to discuss your reasons for taking opioids with your prescriber. Some conditions such as anxiety or depression or post-traumatic stress disorder might increase your risk for long-term opioid use and these conditions can be managed to reduce that risk.

Sometimes, pain may persist for longer than expected after surgery. If significant pain remains beyond 3-6 months, this is called persistent post-surgical pain and it is generally not treated with opioids.

You can also become dependent on opioid medicines if you take them for more than 2 weeks (called opioid dependence).  This means that if you stop taking the drug suddenly, or lower the dose too quickly, you can get symptoms of withdrawal. You may experience symptoms that include worsening pain, anxiety or agitation, tiredness, sweating, a runny nose, stomach cramps, diarrhoea, & aching muscles.

If you take opioids for a short period, you will not develop tolerance or dependence.

You should not share your opioids with others and should dispose of any unused drugs at your pharmacy. Do not save opioids for future use as this may result in accidental overdose.

What about addiction to opioids?

People who are addicted to opioids can:

• Feel out of control about how much medicine they take or how often they take it.

• Develop cravings for opioids.

• Continue to take opioids even when they have a negative effect on their physical or mental health.

Addiction to prescription opioids is more common if you have had problems with addiction to other things in the past like alcohol, smoking or illicit drugs. Addiction may be more common in people with severe depression or anxiety. Also, addiction is more likely if you take opioids for reasons other than pain relief such as reducing anxiety or for help with sleeping.

If you have had a problem with addiction in the past, you may still take opioid medicines for your pain. However, your inpatient pain team will need to know about your past or current drug-taking to prescribe opioids safely and to help you watch out for warning signs of addiction relapse.

Can I take this medicine long-term?

Opioids can cause serious harm if they are taken for reasons other than pain relief. It is important to consider the risks and benefits of continued opioid therapy with your prescriber on a regular basis. Recent medical literature suggests that the risks to your health increase significantly when prescribing opioids at high doses for a long period of time.

If you take opioids for many months or years, it can cause health problems, including:

• Reduced ability to fight infection.

• Increased levels of pain.

• Reduced fertility.

• Low sex drive.

• Osteoporosis (weak bones).

• Irregular periods.

Everyone prescribed opioid medicines longer-term should have their prescription reviewed at regular intervals. If this does not happen ask your GP.

Many people can reduce their opioid dose gradually and find that their pain is no worse and their quality or enjoyment of life is improved, as they experience fewer side effects.

Is there anything else my prescriber needs to know?

• If you are allergic to any drugs or medicines.

• If you are taking any other medicines or herbal medicines.

• If you are pregnant or breast feeding, or if you are planning to become pregnant in the future.

• If you have a kidney problem.

Authors (alphabetical order):

Sara Mahoney: clinical nurse specialist inpatient pain

Lindsey Pollard: clinical nurse specialist inpatient pain

Dr Mark Rockett: consultant anaesthetist and pain medicine specialist

Dr Ross Vanstone: consultant anaesthetist

Dr Stephen Ward-Booth: general practitioner

Dr Tim Wilson: consultant anaesthetist and pain medicine specialist

Corresponding: Dr Mark Rockett mark.rockett@nhs.net