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Can You Take Co-codamol With Naproxen And Diazepam?

Can You Take Co-Codamol With Naproxen And Diazepam

Today I will review the use of three different drugs, which occasionally are prescribed simultaneously or in combination with one another.

This post aims to answer the following question: can you take Co-codamol with Naproxen and Diazepam? As a part of the discussion, I will review the licensed use of each drug and the reasoning for combination treatment. Remember to follow the directions given by your prescriber.


What Is Co-codomol?

What Is Co codamol

Co-codamol is a popular painkiller available on prescription or over the counter (see Co-codamol over the counter) and one of the top drugs prescribed in the UK.

Co-codamol contains two active ingredients.

namely paracetamol and codeine (an opioid analgesic).

Co-codamol: Licensed Use

Co-codamol is a painkiller used to manage acute pain, not relieved by other pain relievers, such as paracetamol or Ibuprofen alone. The lower strength of co-codamol is widely available as a pharmacy-only medication.

‘Standard’ pharmacy-only co-codamol contains 500mg of paracetamol and 8mg of codeine per tablet (Co-codamol 8/500).
For example, Solpadeine max contains 12.8mg of codeine and 500mg of paracetamol per tablet in some branded products.

Co-codamol: Mechanism Of Action

The exact mechanism of action of paracetamol is not known.

Codeine acts on opioid receptors and consequently affects pain signals’ transmission to the central nervous system.

Co-codamol: common side effects

Paracetamol on its own does not produce many side effects. Codeine, on the other hand, is associated with a few common side effects, for example:

Co-codamol: common side effects

  • Drowsiness and sedation
  • Nausea
  • Vomiting
  • Dry mouth
  • Constipation

What Is Naproxen?

Naproxen is another popular prescription painkiller, which belongs to a group of drugs called Non-Steroidal Anti-Inflammatory Drugs (NSAIDs). Another example of NSAIDs, which are commonly available over the counter from pharmacies, is Ibuprofen. Many Naproxen alternative drugs exist and can be prescribed by a doctor.

Naproxen: Licensed Use

Naproxen and other NSAIDs are used to help with pain and inflammation. Naproxen is the most commonly used NSAID as it offers good efficacy with a low incidence of side effects.

Examples of licensed use for which NSAIDs can be prescribed:

  • Conditions characterized by pain and inflammation, including rheumatic disease (osteoarthritis, rheumatoid arthritis) and disorders affecting muscles and bones.
  • Acute gout.
  • Painful menstruation.

Naproxen: Mechanism Of Action

NSAIDs, including Naproxen, have a well-defined mechanism of action. NSAIDs stop the production of prostaglandins, which play a role in the inflammation process.

An increased level of prostaglandins is observed at the site of injury or infection. NSAIDs produce anti-inflammatory and pain relief effects.

Naproxen: Common Side Effects

Naproxen can commonly cause gastro-intestinal side effect, for example:

  • Vomiting
  • Nausea
  • Heartburn / dyspepsia
  • Constipation / diarrhoea

Naproxen Common Side Effects

Individuals who take other drugs or have an underlying condition(s) may be offered Proton Pump Inhibitor (PPIs). Omeprazole (the most popular PPI) is often prescribed together with Naproxen to 'protect' the stomach and minimize gastrointestinal side effects such as heartburn.

What Is Diazepam?

Diazepam differs from previously reviewed Co-codamol and Naproxen as they are not classified as painkillers. Diazepam belongs to a group of drugs called Benzodiazepines. Benzodiazepines are categorized as hypnotics (to help with help) and anxiolytics (to help with anxiety). Commonly Diazepam is also known as a ‘muscle relaxant.’

Diazepam: Licensed Use

Benzodiazepines can be used to manage various conditions. Benzodiazepines are usually prescribed short-term treatment due to their addictive properties (physical dependence) and tolerance (medication does not produce the same therapeutic effect as it initially did).

Examples of conditions treated:

  • Muscle spasm
  • Anxiety
  • Insomnia
  • Sedation during dental procedures

Diazepam: Mechanism Of Action

Diazepam’s exact mechanism of action is complex. In simple terms, Diazepam acts in the central nervous system (brain), affecting the release of chemical substances called neurotransmitters. Benzodiazepines also decrease muscle spasms by stopping the transmission of nerve cells (neurons) and other agents in the spine and brain (Witenko et al., 2014).

Diazepam: Common Side Effects

Quick FAQ

How long before bed should you take diazepam?
It is suggested to take Diazepam exactly before bedtime.
Does diazepam make you gain weight?
Taking Diazepam does affect weight gain.
Does diazepam cause loss of appetite?
Appetite loss occurred in patients with withdrawal symptoms

Benzodiazepines, including Diazepam, can produce many side effects. Common side effects include:

  • Drowsiness
  • Confusion
  • Loss control of body movements (ataxia)
  • Tremor
  • Fatigue
  • Withdrawal symptoms (sweating, tremor, panic, anxiety, palpitations, muscle spasm, loss of appetite)

Diazepam: Common Side Effects

I will now look at the concomitant use of either of the drugs.

As you may have deducted, a combination of two or more of the above medicines may be used in painful conditions (Co-codamol & Naproxen) characterized by muscle spams (Diazepam).

Can You Take Co-codamol With Naproxen And Diazepam?

GP can prescribe a combination of all three drugs at the same time. The logic behind the combination treatment is simple. All medications work differently and, when taken together, produce a cumulative effect. Co-codamol and Naproxen are used for their pain-relieving properties, whereas Diazepam manages muscle spasms.

The use of Diazepam is one of the treatment options in managing muscle spasms as set by (national) the NICE guidelines, which develop recommendations for doctors and other healthcare professionals (NICE, 2020).
Diazepam can be prescribed on its own as a muscle relaxant or in combination with either Co-codamol or Naproxen.

Perhaps, the use of Naproxen and/or Co-codamol to acute manage pain is more straightforward. Diazepam or another muscle relaxant is considered if muscle spasm is widespread or involves different ‘trigger points’ (ibid).

For example, an individual who experiences lower back pain (without sciatica) may be offered, in the first instance, an NSAID (Naproxen).

Codeine/Co-codamol can be offered as an alternative to NSAIDs if NSAIDs are not tolerated or are ineffective. The guide on management of back pain advice against routine use of opioids for acute low back pain.
If muscle spasm is experienced, a GP may consider using Diazepam.

Diazepam would be prescribed on a short-term basis, 2-5 days. Although not contra-indicated, the guide on back pain advises against the use of opioids (Co-codamol) at the same time with Diazepam due to the increased risk of ‘lethal’ sedation. (NICE, 2020)
Despite the advice on possible increased sedation caused by taking Diazepam, co-codamol, and Naproxen as occasionally prescribed together.

Can You Take Co-codamol With Naproxen?

A GP or another prescriber can issue a prescription for a combination of Co-codamol and Naproxen. Both drugs do not interact with each other.

Can You Take Naproxen And Diazepam?

The combination of Naproxen and Diazepam may be considered in acute conditions characterized by muscle spasms. There is no interaction between drugs.

Can You Take Co-codamol With Diazepam?

As previously reviewed, the use of opioids such as Co-codamol at the same time with Diazepam is not recommended. The use of Diazepam with opioids may result in severe sedation, respiratory depression, coma, and death (eMC, 2019).

A combination of both drugs should be considered for patients for whom other treatments and not possible. The combination of Diazepam and opioids should be limited to a short time only.


After careful consideration of the treatment, some patients may be prescribed a combination of Co-codamol, Naproxen, and Diazepam, due to the possible risk of severe side effects. A different mechanism of action for each drug may result in better pain and muscle spasm control.

Patients need to be aware of the sedative properties of both Co-c0damol and Diazepam and the possible risk of severe sedation when a combination of those drugs is prescribed.


eMC (2019). SmPC: Diazepam Tablets BP 10mg.  https://www.medicines.org.uk/emc/product/4522/smpc Accessed on 28/01/2021

NICE (2020). Scenario: Managing muscle spasm pain. Available at: https://cks.nice.org.uk/topics/palliative-cancer-care-pain/management/managing-muscle-spasm-pain/ Accessed on 27/01/2021

Witenko, C., Moorman-Li, R., Motycka, C., Duane, K., Hincapie-Castillo, J., Leonard, P., & Valaer, C. (2014). Considerations for the appropriate use of skeletal muscle relaxants to manage acute low back pain. P & T : a peer-reviewed journal for formulary management, 39(6), 427–435. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4103716/ Accessed on 27/01/2021