Co-codamol is a widely used and easily available medicine that combines two well-known painkilling ingredients – codeine and paracetamol. It is available over-the-counter (OTC) from pharmacies and also via prescription for stronger doses.

It is precisely because it is so common and widely available that side effects from co-codamol can sometimes catch people off guard. This article will cover both the common and the rarer and more serious potential side effects, as well as when they might signal a bigger problem.

 

What Is Co-Codamol?

Co-codamol is a painkiller that combines two painkillers in codeine and paracetamol. It is generally used to treat moderate to severe pain, which can include period pain, muscle pain and toothache, among other types of pain.

It may be prescribed or advised when less potent everyday painkillers such as aspirin, ibuprofen or paracetamol on its own have not been enough.

Although it is available over-the-counter in the UK, that still means that any sale must be discussed with and approved by a pharmacist. Only the lowest strength (containing 8 mg of codeine and 500 mg of paracetamol) can be bought over-the-counter. Stronger doses must be prescribed by a relevant clinician.

The reason for this is that both codeine and paracetamol can be dangerous if taken in too large quantities or misused. Codeine is an opioid and, while it is far less potent than other drugs in the same class such as morphine, oxycodone or hydromorphone, it still carries risks including overdose and dependence.

Paracetamol is relatively safe, but it is possible to overdose if you take too much, so it is always vital to monitor the use of any other medications that may also contain paracetamol. Co-codamol, codeine and paracetamol also carry the risks of a number of common and less common side effects.

 

Common Co-Codamol Side Effects

NICE and the NHS list a number of common side effects, which the NHS defines as those affecting more than one in a hundred people.

Common short-term side effects can include:

  • Constipation
  • Nausea or vomiting
  • Feeling dizzy
  • Feeling sleepy
  • Headaches
  • Dry mouth
  • Flushing
  • Euphoric mood
  • Excessive sweating
  • Palpitations

In general, these symptoms should be relatively minor and should wear off after a short time. In some cases, this could be a number of days. You should always consult your doctor or another relevant medical professional though if they persist or symptoms are severe.

In the case of co-codamol making you feel sleepy or dizzy, you should avoid driving, operating machinery or using any tools that could be dangerous.

 

Side Effects with Prolonged Use

Co-codamol is generally only recommended for short-term use, largely because it carries a risk of both physical and psychological dependence. Users can build a tolerance to the drug quite quickly. This means it becomes less effective at smaller doses, and more and more is needed to achieve the same effect. At the same time, the system adapts to the presence of the drug, and when it is removed or reduced, the individual may suffer a range of unpleasant and potentially dangerous withdrawal symptoms.

The National Institute for Health and Care Excellence (NICE) says that there is an increased risk of dependence and addiction if co-codamol is used for more then three months, even at recommended doses. The risks can be higher with unregulated misuse of the drug. NICE recommends a tapered approach – reducing the dose gradually in order to avoid or minimise withdrawal symptoms.

Long-term codeine use has also been linked to depressive symptoms in some users.

 

Serious Side Effects to Watch For

There are also a number of more serious side effects to watch out for, including the potential of overdosing on the two active ingredients if too much is taken.

The NHS advises that you should call a doctor or 111 for advice if you experience symptoms including a skin rash, difficulty urinating, changes in your vision or muscle stiffness.

You should also seek medical advice if you experience hypotension or low blood pressure.

Symptoms of hypotension can include:

  • Lightheadedness or dizziness
  • Feeling sick
  • Blurred vision
  • Generally feeling weak
  • Confusion
  • Fainting

The codeine party of co-codamol can cause shallow breathing and this can be extremely dangerous if you take too much. If you experience difficulty breathing or short, shallow breathing, you should call 999 or go to A&E immediately.

You should also call 999 or go to A&E if you experience a fit or seizure.

A paracetamol overdose can damage the liver and kidneys. Early symptoms can include abdominal pain, nausea and sickness. These can be easy to mistake for something else, so it is important to make sure you know if you are taking co-codamol with any other medicines containing paracetamol.

 

Signs of Co-Codamol Allergy

It is also possible to have a severe allergic reaction (anaphylaxis) when using co-codamol. This is classed as a medical emergency and can be extremely serious.

Some signs to look out for include:

  • Sudden swelling in the mouth, lips or tongue
  • Tight throat or difficulty swallowing
  • Sudden confusion, drowsiness or dizziness
  • Breathing too fast or struggling to breathe

If you think you may be having an allergic reaction, you should call 999 immediately.

 

Risks of Co-Codamol Misuse

Co-codamol is a combination painkiller with two active ingredients. That means that users need to be aware of the risks associated with both codeine and paracetamol.

The main risk with paracetamol lies in accidentally overdosing if you take too much co-codamol or combine it with other medicines containing paracetamol – including additional doses of paracetamol on its own. Some people may be unaware of the types of medicine that may contain paracetamol, including some cold and flu remedies and some sinus and allergy medications.

It is also possible to overdose on codeine. This may occur if you take too much co-codamol and also if you combine co-codamol with other opioids. Another risk linked to the codeine element is the possibility of developing co-codamol dependence.

 

Getting Help for Co-Codamol Dependence

As already mentioned, co-codamol dependence can develop even from a legitimately prescribed or over-the-counter use of the medicine. This is a relatively common issue and, while it can be very difficult to tackle without expert help and support, co-codamol dependence is treatable.

If you are worried about your co-codamol use, no matter why you started taking it in the first place, get in touch with Ocean Recovery today on 0800 880 7596 for confidential advice on the next steps to take.

John Gillen - Director at Ocean Recovery

John Gillen - Author - Last updated: September 2, 2026

John is one UK’s leading professionals in the addiction recovery industry. Pioneering new treatment techniques such as NAD+ and ongoing research into new therapy techniques such as systematic laser therapy, John is committed to providing the very best treatment for people throughout the UK and Europe. During his extremely busy schedule, John likes to regularly update our blog section with the latest news and trends in the industry to keep visitors to our site as well informed as possible on everything related to addiction treatment.