Managing cancer pain with opioids

Taking opioids regularly can cause difficulty passing bowel motions (constipation). Opioids slow down the muscle contractions that move food through your colon, which can cause hard faeces (stools or poo). To keep stools soft, your treatment team will suggest you take a laxative at the same time as the opioid medicines. You may also be given a stool softener. Drinking 6–8 glasses of water a day, eating a high-fibre diet and getting some exercise can all help manage constipation, but this may be difficult if you’re not feeling well.

This usually improves when you get used to the dose, or can be relieved with other medicines. Sometimes you may need to try a different opioid.

Feeling sleepy is typical when you first start taking opioids, but usually improves once you are used to the dose. Tell your doctor or nurse if you continue to feel drowsy as you may need to adjust the dose or change medicines. Alcohol can make drowsiness worse and is best avoided. Opioids can affect your ability to drive.

Opioids can reduce the amount of saliva in your mouth, which can cause tooth decay or other problems. Chewing gum or drinking plenty of liquids can help. Visit your dentist regularly to check your teeth and gums.

Your body may feel physically tired, so you may need to ask family or friends to help you with household tasks or your other responsibilities. Research shows that stretching or a short walk helps you maintain a level of independence and can give you some energy.

If you have itchy skin, sometimes it may feel so irritated that it is painful. A moisturiser may help, or ask your doctor if there is an anti-itch medicine or a different opioid you can try.

You may not feel like eating. Small, frequent meals or snacks and supplement drinks may help. If the loss of appetite is ongoing, see a dietitian for further suggestions.

Opioids can slow your breathing. This usually improves as your body gets used to the dose. To help your body adapt to how opioids affect your breathing, you will usually start on a low dose and gradually increase the amount. Your doctor may advise you not to drink alcohol or take sleeping tablets while you are on opioids.

This is rare. It is important to tell your doctor immediately if this occurs.

If you stop taking opioids suddenly, you will usually have withdrawal symptoms or a withdrawal response. This is because your body has become used to the dose (physical dependence). Withdrawal symptoms may include agitation; nausea; abdominal cramping; diarrhoea; heart palpitations and sweating.

To avoid withdrawal symptoms, your doctor will reduce your dose gradually to allow your body to adjust to the change in medicine.

Don’t reduce your dose or stop taking opioids without talking to your doctor first. They will develop a plan to gradually reduce the dose.

One reason that some people don’t use opioids is because they worry about becoming addicted to opioids.

When people take morphine or other opioids to relieve acute pain or for palliative care, they may experience withdrawal symptoms when they stop taking a drug, but this is not addiction. A person with a drug addiction problem takes drugs to fulfill physical or emotional needs, despite the drugs causing harm.

Some people who take opioids long term for pain relief are at risk of becoming addicted. The risk is higher for people who have a history of misusing opioids or other medicines before their cancer diagnosis. People who use opioids to manage chronic pain over a long period of time are also at risk of becoming addicted. Talk to your doctor if you are concerned about drug dependence.

Not usually. Strong pain medicines are usually given by mouth as either a liquid or tablet, and work just as well given this way as injection. If you’re vomiting, opioids can be given as a suppository inserted into the bottom, by a small injection under the skin (subcutaneously), through a skin patch or in sublingual tablet form. There are different ways that medicines can be taken.

Opioids can also be injected into a vein for short-term pain relief, such as after surgery. This is called intravenous opioid treatment, and it is given in hospital.

Some people try to avoid taking pain medicine until the pain is severe, thinking it is better to hold out for as long as possible so the medicine works better later. However, this may change the way the central nervous system processes the pain, causing people to experience pain long after the cause of the pain is gone.

It is better to take medicine as prescribed, rather than just at the time you feel the pain.

People with cancer at any stage can develop severe pain that needs to be managed with strong opioids, such as morphine. Opioids are also commonly prescribed after surgery.

Being prescribed opioids doesn’t mean you will always need to take them. If your pain improves, you may be able to take a milder pain medicine or try other ways to manage the pain, or you may be able to stop taking strong pain medicines.

While it’s relatively common for people diagnosed with cancer to get breakthrough pain, this sudden flare-up of pain can be distressing.

You might get breakthrough pain even though you’re taking regular doses of medicine. The pain may happen on occasion or as often as several times a day. This breakthrough pain may last only a few seconds, several minutes or hours. Causes of breakthrough pain may vary. It can occur if you have been more active than usual or have strained yourself. Other causes of breakthrough pain include anxiety, or illnesses such as a cold or urinary tract infection. Sometimes there seems to be no reason for the extra pain.

Talk to your treatment team about how to manage breakthrough pain. They may prescribe an extra, or top-up, dose of a short-acting (immediate release) opioid to treat the breakthrough pain. The dose works fairly quickly, in about 30 minutes.

It is helpful to make a note of when the pain starts, what causes it and how many extra doses you need. This information will help your doctor better understand your pain experience. If you find your pain increases with some activities, taking an extra dose of medicine beforehand may help.

Some people with cancer stop getting pain relief from their usual opioid dose if they use it for a long time. This is known as tolerance. This means that the body has become used to the dose and your doctor will need to increase the dose or give you a different opioid to achieve the same level of pain control. You can develop tolerance without being addicted.

All drugs that affect the central nervous system can affect the skills needed for driving such as reaction times, alertness and decision-making. Doctors have a duty to advise patients not to drive if they are at risk of causing an accident that may harm themselves or others. While taking opioids, particularly during the first days of treatment, you may feel drowsy and find it hard to concentrate, so driving is not recommended.

Before you drive, ask your doctor for advice and consider the following:

• Don’t drive if you’re tired, you’ve been drinking alcohol, you’re taking other medicine that makes you sleepy, or road conditions are bad.
• It is against the law to drive if your ability to drive safely is influenced by a drug. Also, if you have a car accident while under the influence of a drug, your insurance company may not pay out a claim.
• Once the dose is stabilised, take care driving. Keep in mind that changes in dose or stopping opioids suddenly can affect driving, as can using breakthrough pain medicine.
• Special rules and restrictions about driving apply to people with brain tumours, including secondary brain cancer, or people who have had seizures.

• For more information, talk to your doctor or download the Austroad publication Assessing Fitness to Drive.

Stopping opioids suddenly can cause side effects. You should only reduce your dose or stop taking opioids after talking with your healthcare team. They will develop a withdrawal plan (called a taper) to gradually reduce the amount of medicine you take. It may take a few weeks to safely reduce the dose.