How does codeine work?
Codeine is from a group of medicines called opiates, or narcotics. It works in the central nervous system and the brain to block pain signals to the rest of the body. It also reduces the anxiety and stress caused by pain.
When codeine blocks the pain, there are other unwanted effects, such as slow or shallow breathing. It also slows down digestion, which is why codeine can cause constipation.
When will I feel better?
This depends on the type of codeine you take. A codeine injection into a vein gives the quickest pain relief – it works almost straight away. But you can only get this at a hospital.
Codeine tablets, liquid and cough syrup all work in about 30 to 60 minutes, but stop working after a few hours.
Are there any long-term side effects?
Some people with conditions that need long-term pain relief may need to take codeine for a long time.
If you need to take it for a long time your body can become used to it (known as tolerance). That means you may need higher doses to control your pain over time.
Some people can become more sensitive to pain (hyperalgesia). If this happens, your doctor will reduce your dose gradually to help these symptoms.
It's possible to become addicted to codeine. For this reason, your dose will be reviewed to make sure you're only having the amount you need to control your pain.
Your treatment plan may include details of how and when you'll stop codeine.
If you're having treatment for cancer pain or other severe long-term pain, your pain control will be carefully monitored. Speak to your doctor if you're worried about tolerance, hyperalgesia or becoming addicted.
How will I know if I'm addicted to codeine?
If you're addicted to codeine, you may find it difficult to stop taking it or feel you need to take it more often than necessary.
If you stop taking codeine suddenly you may get withdrawal symptoms.
These can include:
- feeling agitated or anxious
- panic attacks
- feeling your heartbeat (palpitations)
- difficulty sleeping
- shaking
- sweating
- body aches
- feeling restless
Talk to your doctor if you:
- are worried about addiction
- need help with addiction
- want to stop taking codeine
How does codeine compare with other painkillers?
The type of painkiller that's best depends on what type of pain you have. If codeine does not get rid of your pain or becomes less effective, talk to your doctor.
Can children take codeine?
Do not give codeine to babies and children under 12.
Children aged 12 to 18 years can take codeine for pain or diarrhoea, but only if other medicines have not worked. Use the lowest dose that works for no more than 3 days. If they still have symptoms after 3 days, see a doctor.
Codeine should not be given to children aged 12 to 18 years if they have breathing problems or if they have had their tonsils or adenoids removed to treat obstructive sleep apnoea.
Is codeine a controlled medicine?
Codeine is a controlled medicine. This means there are extra rules on how it's prescribed and dispensed to make sure it's not given to the wrong person or misused. However, this does not affect you as a patient. The rules only apply to the pharmacy that dispenses it.
Will it make me so sleepy I cannot function?
When you first take codeine, you'll probably feel sleepy for a few days. But the sleepiness will wear off as your body gets used to the medicine.
You might notice you're less alert. In this case, you might choose to take a lower dose and have less than perfect pain relief as a trade-off.
Will it affect my contraception?
Codeine does not stop any type of contraception from working, including the combined contraceptive pill, progestogen-only pill and emergency contraception.
But if you are taking codeine because you have severe diarrhoea for more than 24 hours, your contraceptive pills may not protect you from pregnancy. Check the pill packet to find out what to do.
Find out more:
Can I drive or ride a bike?
Do not drive a car or ride a bike if codeine makes you sleepy, gives you blurred vision or makes you feel dizzy, clumsy or unable to concentrate or make decisions. This may be more likely when you first start taking codeine but could happen at any time, for example when starting another medicine.
It's an offence to drive a car if your ability to drive safely is affected. It's your responsibility to decide if it's safe to drive. If you're in any doubt, do not drive.
Talk to your doctor or pharmacist if you're unsure whether it's safe for you to drive while taking codeine. GOV.UK has more information on the law on drugs and driving.
Can I drink alcohol while taking codeine?
Drinking alcohol while you're on codeine may make you feel more sleepy, and can increase the risk of serious side effects.
It's best to stop drinking alcohol during the first few days of treatment until you see how codeine affects you.
If you feel sleepy with codeine, stop drinking alcohol while you're taking it.
Is there any food or drink I need to avoid?
Apart from alcohol, which you may need to reduce or stop, you can eat and drink normally while taking codeine.
Will recreational drugs affect it?
If you take recreational drugs, such as cannabis, cocaine or heroin, while you're taking codeine, you're more likely to get the serious side effects of codeine including breathing difficulties, heart problems or having a fit or seizure. On rare occasions, this may even result in a coma.
Some recreational drugs, such as cannabis, will also increase codeine side effects such as sleepiness and dizziness.
Taking heroin while you're on prescribed codeine is especially dangerous. You're more likely to get all the side effects of codeine, including addiction.
Tell your doctor if you think you may take recreational drugs while you're on codeine.
Find out more about the side effects of recreational drugs on the Frank website.