Opioids provide pain relief by acting on areas in the spinal cord and brain to block the transmission of pain signals. Opioids are considered to be some of the strongest painkillers available and are used to treat pain after surgery, serious injury and cancer. Examples of these include codeine, dihydrocodeine and co-codamol (which contains paracetamol and codeine).

What dose of opioid should I take?

The correct dose of any medicine is the lowest dose that produces a noticeable benefit. It is not usual to get complete relief of pain from opioids. Your GP may recommend an “opiate trial” for 2-3 weeks, then review if the benefits of taking the medication outweigh the risks. You should always take the correct dose of prescribed medicines. If you feel the dose isn’t enough, or if the side effects interfere with your life, discuss this with your GP.

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 If pain has affected your sleep, opioids may help you to recover your normal pattern of sleep, but they should not make you drowsy in the daytime. Opioid medicines can cause some problems when you take them for long periods of time.

These problems include:

• constipation*
• itching
• weight gain
• lack of sex drive

* This is common when taking opioids and does not tend to go away the longer you take opioid medicines. You may need to try laxatives to treat constipation.

Can I drink alcohol?

Alcohol and opioids both can cause sleepiness and poor concentration. You should avoid alcohol completely when you first start on opioids or when your dose has just been increased.

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 medicines (dependence).

What about addiction to opioids?

It is rare for people in pain to become addicted 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
• crave the drug
• continue to take the drug even when it has a negative effect on their physical or mental health

Can I take this medicine long-term?

While opioids can have a positive benefit for some people living with long-term pain they can have serious consequences when they are not providing sufficient benefit or are being taken in a manner that was not intended. 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.