What are opioids?

Opioids (sometimes called opiates) are medicines used to treat pain.

There are many different types of painkillers that are suitable for different types of pain. Most doctors will start off prescribing a lesser strength painkiller such as paracetamol or ibuprofen.

If these do not work, depending on the type of pain you have, your doctor may consider prescribing a strong painkiller such as an opioid.

Types of opioids

Opioid medications are usually divided up into two groups:

• Weak opioids – these include codeine and dihydrocodeine.
• Strong opioids – these include tramadol, buprenorphine, methadone, diamorphine, fentanyl, hydromorphone, morphine, oxycodone, and pethidine.

Even though the strong opioids are classified together, they can also vary a lot in strength. The stronger ones may be ten times stronger than the weakest. Strong opioids are usually prescribed for more severe types of pain – for example, immediately after an operation. They are also often used for pain in people with cancer. Strongest painkillers over the counter

The weaker opioids are usually taken as tablets. There are dispersible and liquid forms. They may come in brands which combine paracetamol and the opioid.

Strong opioids can be taken as:

• Liquid or syrup.
• Quick-acting tablets and capsules.
• Slow-release tablets and capsules.
• Sachets.
• Tablets that are held in the mouth – next to the gum (buccal tablets).
• Patches for the skin.
• Intranasally (fentanyl spray).
• Injections, which may be under the skin, into the vein or into a muscle.

They all come in various different brand names. Once you have started taking one brand it is usually best to avoid changing to a different one to avoid confusion or mistakes. Best pain killer tablet for body pain

Although there are several different types of strong opioid, the most commonly prescribed is morphine.

How do opioids work?

Opioids work by attaching to opioid receptors in the brain and spinal cord, the gut and other parts of the body. This leads to a decrease in the amount of pain felt.

How are opioids taken?

Each different opioid medicine will have different instructions. The doctor and pharmacist will explain exactly when and how to take them.

Morphine

The principles of taking morphine are important and it is a good idea to understand how and why morphine is prescribed in a certain way.

To start off with, it is usual to be given a quick-acting strong opioid (morphine tablets or liquid) as well as a slow-release morphine tablet or capsule. The slow-release preparation is usually taken once or twice a day, depending on the brand. Slow-release preparations give a steady level of medicine in the body throughout the day.

However, pain may be experienced before the next dose of slow-release morphine is due; this is called ‘breakthrough’ pain. Quick-acting morphine is used to ease breakthrough pain. It can be taken every four hours (or even more frequently in end-of-life care), when needed.

The slow-release morphine is started at a very low dose and increased over a number of weeks until the symptoms have eased. It is important to document how much quick-acting morphine is being used each day. This information can then be used to increase the dose of the slow-release morphine to keep people pain-free. Strong pain killer naproxen

Slow-acting morphine which is taken twice daily should ideally be taken 12 hours apart eg, at 8am and 8pm. If two doses are taken closer together, eg 10 hours apart, then the night-time gap between doses will be longer and the pain may recur.

Side-effects of opioids

As with all medicines, opioids have a number of side-effects. In general, the stronger the opioid, the more likely the side-effects are. The most common side-effects are constipation, feeling sick (nausea) and drowsiness.

• Constipation – when starting treatment with an opioid, a laxative will also usually be prescribed. Laxatives help to ease and prevent constipation by softening the poo (stools), making it easier to pass, or they stimulate the bowel to push the stools along more quickly.
• Nausea – feeling sick is a common side-effect when first starting an opioid. This usually passes after a week or so, once the body gets used to this medication. A doctor will prescribe an anti-sickness medicine (an antiemetic) if you feel sick. If the sickness lasts for more than a week this is unusual but changing to a different opioid may help. Strong pain killer
• Drowsiness and tiredness – again, this usually passes once used to this medication Drinking alcohol as well as taking an opioid may increase drowsiness, especially at the start of treatment or when the dose is being increased. It is better to avoid alcohol if you are taking an opioid, or to drink less alcohol than usual.
• A dry mouth can also be a problem. Some people find drinking plenty of liquids or chewing gum may help with this.

If the dose is too high, these medicines can:

• Cause significant drowsiness.
• Cause confusion.
• Cause dizziness or fainting – signs of low blood pressure (hypotension).
• Cause hallucinations (seeing things that are not there).
• Affect breathing.

These side effects need to be reported to a medical professional. The dose of the opioid may need to be decreased.

If wearing a prescribed fentanyl patch, this should be removed from the skin straightaway and medical advice should be sought if these problems develop: