COMMON QUESTIONS ABOUT MORPHINE

by Dr Robert Twycross MA DM FRCP, Macmillan Clinical Reader in Palliative Medicine, University of Oxford
Dr Sylvia Lack, Consultant in Hospice Care, Waterbury, Connecticut

What is morphine and how does it work?

Morphine is a naturally-occurring substance obtained from the juice of the opium poppy. Codeine comes from the same source. Both substances are effective in relieving pain, cough and diarrhoea. Morphine is a stronger pain-killer and tends to be reserved for when codeine (or a similar drug) fails to relieve pain. Morphine and codeine ease pain by acting on pain centres in the brain and spinal cord,

Morphine? Does that mean I am at the end of the road?

Many patients need morphine before and after a major operation or after a heart attack. In these circumstances, the use of morphine clearly does not mean that the person is about to die. It is important that the reason for the use of morphine in cancer is fully understood. Morphine is used to control pain which no longer responds to codeine or a similar drug. It is used at many different stages of the illness, and not just at the end of the road.

Some cancer patients never need morphine. Many need it for weeks, months or years because of continuing pain. Others need it for just a few days or weeks - perhaps when very ill and close to death.

Doesn't morphine speed things up - make you die sooner?

There is no evidence that this is so. Over the years, we have seen many patients take on a new lease of life when free of pain and able to sleep comfortably through the night. Freed from the nightmare of never-ending pain, a patient can take a renewed interest in food, and in life more generally.

Will morphine take the pain away completely?

In many cases yes. Relief, however, may well be incomplete with:

• Bone pain.
• Nerve compression pain.
• Bedsore pain.

Though even with these, many patients have excellent results with morphine.

Certain pains should not be treated with morphine at all. For example:

• Burning and stabbing pain caused by nerve damage.
• Muscle spasm pain.
• Arthritis and spondylosis.
• Tension headache and migraine.

Other remedies exist and will, we hope, be recommended by your doctor.

If I take morphine now, will there be anything stronger for me when the pain gets worse?

The first thing to get straight is that the pain may never get worse. If it does, an increase in the dose of morphine will control the pain again. This may be a permanent increase, but some patients find they can reduce the dose again later. This frequently happens, for example, after a course of radiation therapy to a painful bone.

Second, there is no need for anything stronger because there is no upper limit to the dose of morphine you can take. In fact, few patients ever need more than 200mg by mouth every 4 hours, and most are well controlled on much lower doses (60mg or less).

If a new pain develops that does not respond to morphine, other treatments can be tried.

Wouldn't it be better to keep off morphine until things become really unbearable?

It sounds as if you are worried that your body will 'get used' to morphine and then there will be nothing left to relieve the pain. This does not happen. If a pain returns while you are taking morphine, control will be regained by increasing the dose.

Will I need bigger and bigger doses to control the pain?

Studies have shown that the dose of morphine usually increases over a period of time. However, these same studies show that the longer someone is on morphine therapy:

• The rate at which the dose rises is slower.
• The intervals between dose increases are longer.
• The chance that the dose will be reduced is greater
• The chance of stopping morphine altogether is greater.

How long can I go on taking morphine? Does the effect wear off eventually?

If you need morphine you will be able to go on taking it with good effect for the rest of your life, whether this is months or years.

Normally, the effect does not wear off. The most common reason for an increase in dose is not so much that the morphine effect is wearing off, but that the cancer is causing more pain.

Will I become addicted?

What most people mean by this is, 'Will I become hooked and unable to stop the morphine, even if I no longer need it for pain control?' The answer is a definite 'No!' Over the years, we have treated several thousand cancer patients with morphine. We have never had trouble stopping treatment because of 'addiction'. However, you should not stop taking morphine suddenly and completely. If you no longer need morphine for pain control, the dose can be reduced step by step under your doctor's supervision.

The reason for a gradual reduction in dose is because people who have taken morphine regularly for several weeks usually develop 'physical dependence'. This is not the same as addiction but it does mean that, if morphine is stopped suddenly and completely, withdrawal symptoms would develop.

There is, however, no medical reason for stopping morphine therapy suddenly and completely. If your pain lessens because of radiation therapy, the morphine will be reduced over several weeks. Moreover the amount needed to prevent withdrawal symptoms is only about one-quarter of the previously used pain-relieving dose of morphine. This means, for example, after a successful injection to deaden a painful nerve, it is possible to reduce the dose of morphine considerably and immediately - and to continue reducing the dose more slowly after that - without any upset at all.

What is the difference between morphine in solution and morphine tablets?

Morphine works equally well whether given in solution or as tablets. Commercial solutions are available in differing concentrations. The more concentrated of these can be mixed with your choice of other liquid (e.g. fruit juice, milk) to mask the bitter taste of morphine.

Tablets come in two varieties: standard and long-acting. Most patients start either on morphine solution or standard tablets every four hours. When a stable dose is achieved, patients generally prefer long-acting tablets because they need to be taken only twice a day.