Codeine phosphate

  • Codeine is used to ease pain.
  • The most common side-effects are constipation, drowsiness and feeling sick.
  • Do not take more codeine than your doctor has recommended for you.

About codeine

Type of medicine Opioid analgesic (painkiller)
Used for Pain relief
Also called Codeine phosphate
Available as Tablets, oral liquid, and injection

Codeine is used to control mild-to-moderate types of pain. It works by binding to certain receptors (called opioid receptors) in your brain, which reduces the pain that you feel. Codeine is also sometimes used to help ease a dry cough. It may also be prescribed to help control short episodes of diarrhoea.

Codeine is also contained in a number of combination medicines, some of which can be bought over the counter in pharmacies. These over-the-counter preparations are for short-term use to relieve pain only. There is a separate medicine leaflet called 'Co-codamol for pain relief' which explains about this.

Before taking codeine

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking codeine, it is important that your doctor or pharmacist knows:

  • If you are pregnant or breast-feeding.
  • If you have any breathing problems, such as asthma or chronic obstructive pulmonary disease (COPD).
  • If you have heart, liver or kidney problems.
  • If you have prostate or thyroid problems.
  • If you have epilepsy or low blood pressure.
  • If you have gallstones or a problem with your bile duct.
  • If you have been constipated for more than a week or have an inflammatory bowel problem.
  • If you have ever been dependent on drugs or alcohol.
  • If you have recently had a severe head injury.
  • If you have myasthenia gravis (a condition causing muscle weakness).
  • If you have ever had an allergic reaction to this or to any other medicine.
  • If you are taking any other medicines, including those available to buy without a prescription, herbal and complementary medicines.

How to take codeine

  • Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The leaflet will give you more information about the specific brand of codeine you have been given, and a full list of possible side-effects from taking it.
  • Take codeine exactly as your doctor has told you. Your dose will also be on the label of your pack. You can take codeine before or after food.
  • If you forget to take a dose, take it as soon as you remember and then continue as before. Do not take two doses together to make up for a forgotten dose.

Getting the most from your treatment

  • If you drink alcohol, ask your doctor for advice before taking codeine and alcohol. Your doctor may recommend you do not drink alcohol while you are on this medicine, as it increases the possibility of side-effects such as dizziness and feeling sleepy.
  • Do not take codeine for longer than you have been advised by your doctor. This is because repeatedly using codeine may lead to your body becoming dependent on it. When you then stop taking it, it will cause withdrawal symptoms such as restlessness and irritability. If you are concerned about this, discuss it with your doctor or pharmacist.
  • If you are having an operation or dental treatment, tell the person carrying out the treatment that you are taking codeine.
  • If you buy any medicines, check with a pharmacist that they are safe to take with codeine.
  • If you are having injections of codeine and you are planning a trip abroad, you are advised to carry a letter with you from your doctor. This advice does not apply to the tablet and oral liquid forms of codeine.

Can codeine cause problems?

Along with their useful effects, all medicines can cause unwanted side-effects although not everyone experiences them. These usually improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.

Common codeine side-effects What can I do if I experience this?
Feeling or being sick, abdominal pain Stick to simple meals - avoid rich or spicy foods. Also, try taking your doses of codeine after food, as this may help protect your stomach
Constipation Eat a well-balanced diet and drink plenty of water each day. If this continues to be a problem, speak with your doctor
Feeling dizzy or sleepy If this happens, do not drive or use tools or machines. Do not drink alcohol
Dizziness, particularly when getting up from a sitting or lying position Getting up more slowly should help. Also, make sure you drink plenty of water each day
Dry mouth Try chewing sugar-free gum or sucking sugar-free sweets
Other common side-effects include: disturbed sleep, headache, mood changes, feeling confused, difficulties passing urine, flushing, sweating, rash, and itching If any of these become troublesome, speak with your doctor

If you experience any other symptoms which you think may be due to this medicine, speak with your doctor or pharmacist.

How to store codeine

  • Keep all medicines out of the reach and sight of children.
  • Store in a cool, dry place, away from direct heat and light.