Opioids for Persistent Pain

Opioids have been around for a long time. They have been used for managing pain for centuries. They are commonly used for treating acute pain and for treating pain in the terminally ill, particularly cancer pain. A more recent development is their use in treating persistent pain (often referred to as chronic, non-terminal, non-malignant or non-cancer pain). It is still a subject of debate in the medical profession. Here is a summary of some recent data and views on the issue.

The opium poppy’s role in history as a cause of wars, criminal activity and widespread addiction is well known. It is ingrained in our culture. Small wonder then that the use of medicines derived from this innocent looking flower excites concerns and fears. Opioids are medicines that are chemically similar or act in the same way as extracts of the opium poppy. Morphine and codeine are well-known examples.

Weak or Strong?

Sometimes opioids are described as being weak or strong. But this may not be relevant to you: A weak opioid might be just the right drug for one person. A strong opioid might fail to give any help whatsoever. Modern research is looking at how our individual genetic make-up affects our response to medicines. It helps to explain why this is the case.

Medicines like opioids act through the body to alter its own chemical responses. In order for the body to be able to respond to a medicine, the part of the body that is being acted on must be able to recognize the medicine. The body’s recognition and response involves regions on the surface of the body’s cells called receptors.

There are differences in the way receptors work. These differences account for a lot of the differences between people in the way we respond to drugs, what dose works and what side effects we feel. There is no one size fits all. You and your doctor have to work it out between you whether opioids are for you and if so which one and what dose.

See the box Cells, genes and finding the right medicine for more detail.

Different kinds of opioids

There are many different modern opioid medicines. They come in many forms – tablets that release the drug in the mouth, pills that you swallow, injections, patches to apply to the skin and others. Opioids are useful for some kinds of persistent pain but not all.

Opioids are not the whole answer

As with all medicines, opioids can never be a panacea. They will always work best when they are part of a whole package of care aimed at helping you manage your pain.

The aims of managing pain and of opioid therapy are:

 Improving what you can do
 Improving your comfort
 Improving your psychological well-being
 Improving your quality of life

It is worth remembering that what you do to help yourself is at least as important as any medication you try. If your life is badly affected by persistent pain you can ask your doctor to refer you to a pain management programme. These aim to help you become better at managing pain in the long term. Pain Concern publishes some useful leaflets on self-help (see details at end of article).

Following guidelines

Doctors do not try opioids as a first option; other drugs are likely to be effective in many cases and will be tried first. This is in accordance with World Health Organization guidelines. These were originally developed for relief of cancer pain, but doctors treating non-cancer pain also follow them. Your doctor will consider long-term opioid therapy only if a short-term trial has shown that opioids help your pain.

Not for everyone

Some persistent pain will not be relieved by opioids. When pain does not respond progressively to increasing the opioid dose, doctors say the pain is “opioid-insensitive pain”. The most common cause of this type of pain is physical nerve damage – such as crushed nerves. There are recent doubts about the value of opioids in treating lower back pain as well. Of course, the only sure way of finding out if opioids are going to work is to try them. It is frustrating for both you and your doctor if they prove of no value, so your doctor will assess your suitability for opioid therapy very carefully.

How do they work?

Recent research tells us that opioids are particularly good at controlling how pain is perceived (in other words what the pain feels like). This is because cells in the part of the brain that controls pain perception have lots of opioid receptors. So, in some cases the benefit is not that the pain has gone away or even that it is less severe, but that the opioids allow the person to tolerate it better.

Why the caution?

There are several problems with using opioids. Some relate to the medicines themselves and some to their legal status, making it harder for doctors to prescribe these medicines. There are social concerns about releasing opioids into society. Then there is the feeling some people with persistent pain have that they should not be taking them at all. As we said at the beginning opioids have had a pretty bad press.

Addiction and abuse

This has been a matter of differing opinions between doctors. One side of the argument goes like this: drug addicts are not in pain and the medical use of opioids does not create drug addicts. This is countered by saying that denying addiction risk during opioid treatment of persistent pain does not help doctors use these drugs safely. This aspect of prescribing opioids worries doctors. A recent survey showed that 84% of doctors prescribing opioids were concerned about abuse of the medicine and 75% were concerned about addiction developing.

At one US clinic the level of opioid misuse amongst persistent pain patients was alarming. Of 196 patients monitored a third, 62, committed opioid misuse either by misusing their prescribed medicines or by obtaining opioids from other sources. These patients were more likely to be male and to have a history of alcohol or drug abuse. Doctors therefore face a dilemma when prescribing opioids for some one who had misused drugs in the past. They not only have to consider the patient but also who else might be given access to the drugs they supply.

Side effects

Side effects are the more common problem. Your doctor will describe the possible side effects and may prescribe some simple medicines to help alleviate them. The data sheets that come with the medicines also describe possible side effects and The British Pain Society has a useful leaflet on opioids that, again, goes into detail (see details at end of article). The trouble with long lists of side effects is that they can blur the message that for some people opioids are the only medical option. And in many people, the side effects wear off or are treatable with simple cures. Each person has to work out whether the main problem is drug side effects or the pain itself and the effect that it is having on their life. Living with some unwanted effects of the drug might be a lot better than that.

The most serious side effect of opioids is depression of breathing and this can be fatal in cases of massive overdose. Opioids depress a baby’s ability to breathe properly, so doctors may not want to prescribe them during pregnancy.
There is also some evidence that opioids can affect sex drive and lower resistance to infections. But persistent pain also has these effects, so again each person has to weigh the pros and cons.

The commonest side effects are feeling sick (nausea), dizziness and constipation. These can be treated. In the early stages side effects such as drowsiness might be troublesome.

Tolerance can also be a problem. Tolerance is the need for higher and higher doses to achieve the same effect, even though the pain is not getting worse.

How are opioids used?

Your doctor may want a urine sample to monitor for drug and alcohol abuse before starting opioid therapy. In the first few weeks of therapy, your doctor will monitor your progress quite closely. During this period it is quite likely that the dose will be altered depending on the level of pain relief and how bad any side effects are. Therapy can fail at this stage. Often this is because people don’t follow their doctor’s instructions on how much medicine to take and when. It is tempting to skip a dose if you are not in much pain but this can make finding the right long-term dose extremely difficult.

Once the early stages are over you and your doctor may decide to keep the opioid treatment going, if it is helping you to lead a more normal life and if side effects are not too troublesome. At this point you may feel that you depend on the medicine, because it is helping so much. This is not the same as addiction. People living with persistent pain have a long term condition and depend on medicines in the same way as some one with diabetes or Parkinson’s.

Stopping opioids

Talk to your doctor first if you want to stop taking opioids or if you want to reduce your dose. Your doctor will give you a plan of gradual dose reduction. This will avoid unpleasant withdrawal symptoms.

The last word

Opioids can never be the complete answer to persistent pain. But if they help you to do more and to enjoy life more then you may want to discuss with your doctor the benefits and problems of long term therapy. There is no evidence that long-term opioid use creates irreversible physical harm, although side effects can be troublesome. Not all people with persistent pain should be treated with opioids. However, if you are one of the small number of people who are helped by opioids then you have the right to seek that relief. Increasingly studies are finding that opioids can be safe and effective for managing persistent non-cancer pain if used sensibly.


Further Reading
Opioid Medicines for Persistent Pain, Information for patients and Pain Management Programmes for Adults, Information for patients. Two useful booklets (£1.00 each) available from The British Pain Society, Third Floor, Churchill House, 35, Red Lion, Square, London, WC1R 4SG. http://www.britishpainsociety.org or http://www.britishpainsociety.org/patient_publications.htm - direct link to their most up to date publications.

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