Codeine is a painkiller. It’s used to treat pain, for example after
an operation or an injury. It’s also used for long-standing pain when
everyday painkillers, such as aspirin, ibuprofen and paracetamol, haven’t worked.

Codeine is also used to treat diarrhoea.

Codeine is available on prescription. It comes as tablets, a liquid
to swallow and as an injection. Codeine injections are usually
only given in hospital.

You can buy lower-strength codeine from a pharmacy. It comes mixed with paracetamol (co-codamol), with aspirin (co-codaprin), or with ibuprofen (Nurofen Plus).

You can also buy codeine from a pharmacy as a syrup (linctus) to treat dry coughs.

  • Codeine works by stopping pain signals from travelling along the nerves to the brain.
  • The most common side effects of codeine are constipation, feeling sick and feeling sleepy.
  • It’s possible to become addicted to codeine, but this is rare if you’re taking it to relieve pain and your doctor is reviewing your treatment regularly.
  • It may be best not to drink alcohol while taking codeine as you’re more likely to get side effects like feeling sleepy.
  • Do not give codeine to children under 12 years old. Only give codeine to children aged 12 to 18 years if everyday painkillers like paracetamol and ibuprofen haven’t worked.

Codeine can be taken by adults and children aged 12 years and older.

Only give codeine to children (aged 12 to 18 years) if everyday painkillers such as paracetamol and ibuprofen haven’t worked.

Codeine is not suitable for some people. Tell your doctor before starting the medicine if you have:

Do not give codeine to children who are under 18 years old and have had their tonsils or adenoids removed because it can lead to a sleep problem called obstructive sleep apnoea.

Codeine is not generally recommended in pregnancy. Tell your doctor
before taking codeine if you’re trying to get pregnant, are already
pregnant or if you are breastfeeding.

It’s important to take codeine as your doctor has asked you to.

Take codeine with, or just after, a meal or snack so it’s less likely to make you feel sick.

You can take codeine at any time of day but try to take it at the same times every day and space your doses evenly.

Different types of codeine

Codeine comes as:

  • tablets – these contain 15mg, 30mg or 60mg of codeine
  • a liquid that you swallow – this contains 25mg of codeine in a 5ml spoonful
  • cough syrup – this contains 15mg of codeine in a 5ml spoonful
  • an injection (usually given in hospital)

How much to take

The usual dose of codeine is 15mg to 60mg. You can take this dose up to 4 times a day.

For treating pain:

  • adults usually take one or two 30mg tablets every 4 hours
  • children (aged 12 to 18 years) usually take one or two 30mg tablets (or one or two 5ml spoonfuls of liquid) every 6 hours
  • elderly people or people with kidney or liver problems usually take a 15mg tablet every 4 hours

For treating diarrhoea:

  • adults usually take one or two 30mg tablets (or one or two 5ml spoonfuls of liquid) every 4 hours
  • children (aged 12 to 18 years) usually take one or two 30mg tablets (or one or two 5ml spoonfuls of liquid) every 6 hours
  • elderly people or people with kidney or liver problems usually take a 15mg tablet every 4 hours

For treating a cough:

Adults and children usually take one or two 5ml spoonfuls of cough syrup every 4 to 6 hours.

It’s safe to take codeine with paracetamol, ibuprofen or aspirin.

Some painkillers that you can buy without a prescription from pharmacies contain codeine. They include co-codamol, Nurofen Plus and Solpadeine.

Do not take codeine-containing painkillers that you can buy alongside
prescribed codeine. You’ll be more likely to get side effects.

Like all medicines, codeine can cause side effects in some people – but many people have no side effects or only minor ones.

The higher the dose of codeine the more chance that you will get side effects.

Common side effects

Common side effects happen in more than 1 in 100 people. Talk to your
doctor or pharmacist if the side effects bother you or don’t go away:

  • constipation
  • feeling or being sick (nausea or vomiting)
  • feeling sleepy
  • confusion, feeling dizzy and vertigo (a sensation of spinning)
  • dry mouth
  • headaches

Serious side effects

Serious side effects happen in less than 1 in 100 people. Call a doctor straight away if you get:

  • heart problems
  • seizures
  • breathing difficulty or short shallow breathing
  • muscle stiffness
  • symptoms of low blood pressure, which include feeling dizzy and tired

Serious allergic reaction

In rare cases, it’s possible to have a serious allergic reaction (anaphylaxis) to codeine.

What to do about:

  • constipation – try to get more fibre into your diet such
    as fresh fruit and vegetables and cereals. Try to drink several glasses of water or other non-alcoholic liquid each day. If you can, it may also help to do some gentle exercise. It’s safe to use a laxative if your constipation doesn’t go away. Usually, lactulose is best but check with a pharmacist or doctor first.
  • feeling or being sick (nausea or vomiting) – take codeine with, or just after, a meal or snack to ease feelings of sickness. This side effect should normally wear off after a few days. Talk to your doctor about taking an anti-sickness medicine if it carries on for longer.
  • feeling sleepy – this side effect
    should go away within a few days as your body gets used to codeine. Talk to your doctor if it carries on for longer.
  • confusion, feeling dizzy and vertigo – if codeine makes you feel dizzy when you stand up, try getting up very slowly or stay sitting down until
    you feel better. If you begin to feel dizzy, lie down so that you don’t
    faint, then sit until you feel better. This side effect should wear off
    within a few days as your body gets used to codeine. Talk to your
    doctor if it carries on for longer.
  • dry mouth – try chewing sugar-free gum or sucking
    sugar-free sweets. Your doctor can also prescribe an artificial saliva
    substitute to keep your mouth moist. This comes as a spray, gel or
    lozenge.
  • headaches – it’s safe to take an everyday painkiller such as paracetamol or ibuprofen. Talk to your doctor if the headaches get worse or last longer than a week.

Codeine isn’t recommended during pregnancy and while breastfeeding.

In early pregnancy, it’s been linked to problems in the unborn baby.
If you take codeine at the end of pregnancy there’s a risk that your
newborn baby may get withdrawal symptoms or be born addicted to codeine.

However, it’s important to treat pain in pregnancy. For some pregnant
women with severe pain, codeine might be the best option. Your doctor
is the best person to help you decide what’s right for you and your
baby.

For more information about how codeine can affect you and your baby during pregnancy, read this leaflet on the Best Use of Medicines in Pregnancy (BUMPS) website.

Codeine and breastfeeding

Codeine isn’t usually recommended if you’re breastfeeding. Small
amounts of codeine pass into breast milk and can cause breathing
problems in the baby.

Some medicines and codeine interfere with each other and increase the chances of you having side effects.

Tell your doctor if you’re taking any medicines:

  • to help you sleep
  • for depression – some types can’t be taken with codeine
  • for anxiety, agitation or mental illness
  • for high blood pressure
  • to help stop you feeling or being sick
  • to treat symptoms of an allergy

Mixing codeine with herbal remedies and supplements

It’s not possible to say that complementary medicines and herbal remedies are safe to take with codeine. They’re not tested in the same way as
pharmacy and prescription medicines.

They’re generally not tested for the effect they have on other medicines.

How does codeine work?