Pain Medication

Pain medications are very useful for short term, acute pain whilst the body is healing. However, outside of the normal range of healing the best we can expect from pain medications is a partial improvement in pain.
They are not a cure for pain and come with a variety of side effects. In trials about a quarter of people benefit from taking pain medicines which on average only provide one third reduction in pain levels. It is important to weigh up the advantages of taking them against the disadvantages.

They can be used to quieten pain, to break the pain cycle, and allow for self-care methods of pain management to be implemented. It may be useful to set a goal that you intend to achieve as a result of starting a new medication.

With all pain medications, their effectiveness should be under constant review. Their aim should be to improve quality of life and function. If there is no perceived benefit from taking them they should be stopped. Sudden cessation of pain medication is generally not advised, due to the risk of withdrawal, and so this should be done in a controlled fashion with guidance from your GP.

The following section will explain the various pain medications in more detail.

NSAIDs: Non-steroidal anti-inflammatory medications

Examples in this class of medication include ibuprofen, naproxen and diclofenac. As their name suggests they are anti-inflammatories and are useful in treating conditions such as arthritis and post-operative pain. They work by reducing the amount of prostaglandin produced which is a chemical responsible for pain, fever and inflammation.
For more information: https://www.britishpainsociety.org/static/uploads/resources/files/FPM-NSAID-2018-Final_0.pdf

Paracetamol

Paracetamol is cheap and generally a very safe medication if taken at the correct dose. It is useful for mild to moderate pain and fevers. We are not completely sure how paracetamol works. It could work in a similar way to ibuprofen acting on prostaglandins (see above), or it may act on cannabinoid receptors.

Opioids – morphine-based medications

These are strong analgesics that are used especially within the acute setting for pain after surgery. They are not recommended for chronic pain as they are addictive and tolerance can occur. If we take morphine on a regular basis, our body increases the amount of morphine receptors we have and so we crave more morphine to stimulate these new receptors. This explains why, in the long term, morphine can actually make pain worse.

Our own endorphins act on these same receptors. For example, after a run some people experience a ‘runners high’ due to the release of endorphins, our body’s natural opioids. Other activities that can increase our own endorphins include laughing, yoga and meditation. When endorphins are released and stimulate these opioid receptors, we feel happy and better able to cope with pain and stress.

Unfortunately, opioids are not as effective as our own endorphins, causing multiple side effects and even harm. Morphine activates other receptors causing constipation, nausea and vomiting, drowsiness and impaired cognition. It can also cause hormonal changes, leading to hair loss and menstrual cycle disruption. In older people, morphine increases the risk of falls and fractures.

Historically, the pharmaceutical industry encouraged doctors to prescribe opioids to patients experiencing various types of pain including chronic pain, advertising that they were safe and effective. This has lead to the opioid epidemic, which describes an increase in opioid misuse, overdoses and death from prescription opioids. We are now more aware of the long term risks of taking regular morphine. We know that doses of morphine above the equivalent of 120mg of oral morphine a day do not provide any additional pain relief, but contribute to a higher risk of side effects.

Codeine is a precursor to morphine which is converted in our body. This conversion is determined by our genetics. Approximately 1 in 10 people will not experience any benefit from this medication.

Tramadol is also subject to conversion, but less so than codeine. It can be used for breakthrough pain relief for nerve-type pains.

For more information: https://www.fpm.ac.uk/opioids-aware

Cannabis-based medications

There are only two conditions that cannabis-based medications are currently licensed for, spasticity in multiple sclerosis and rare forms of epilepsy in children. There is poor evidence for the use of cannabis-based medications compared with codeine for chronic musculoskeletal pain.
Currently, there is limited evidence for the use of cannabis-based medications for chronic pain and we cannot prescribe these. We keep up to date with National Clinical Guidance in case the situation changes.

Nerve pain medications

Gabapentin & Pregabalin

These are both anti-epileptic medications used at a lower dose for nerve pain. Nerve pain may not respond to conventional pain relief such as paracetamol and ibuprofen. These medications are started at a low dose and the dose gradually increased if tolerated. They need to be stopped slowly if they do not help. Side effects can include sedation, withdrawal and weight gain. Weight gain may be offset by the ability to increase activity levels with improved pain control.

For more information:

Gabapentin:
https://www.britishpainsociety.org/static/uploads/resources/files/FPM-Gabapentin_0.pdf
https://doclibrary-rcht.cornwall.nhs.uk/DocumentsLibrary/RoyalCornwallHospitalsTrust/PatientInformation/Pain/RCHT1650Gabapentin.pdf
Pregabalin:
https://www.britishpainsociety.org/static/uploads/resources/files/FPM-Pregablin_2.pdf
https://doclibrary-rcht.cornwall.nhs.uk/DocumentsLibrary/RoyalCornwallHospitalsTrust/PatientInformation/Pain/RCHT1654Pregabalin.pdf

Amitriptyline, Duloxetine & others

Amitriptyline was co-incidentally identified as a nerve pain reliever when it was previously used as an antidepressant. Lower back pain was improved in those taking amitriptyline for low mood. It is usually taken at night as it is likely to make you drowsy. This side effect can be used to help sleep, although it is not natural sleep and it is common for people to notice a hangover effect the following morning. Other side effects include dry mouth and constipation. There is thought to be some genetic differences in how this drug is broken down in the body, which is why individuals will experience varying effects to others. There is not a clear standard dose for effective neuropathic pain relief, but as everyone is different it is advised to start at a low dose.

Duloxetine is a modern antidepressant. It is useful for pain related to diabetes, overactive bladder, nerve pain and depression.

Lidocaine (local anaesthetic) plasters and chilli (capsaicin) creams or plasters are also used to treat nerve pain.

See the links below for more information on these medications:

Amitriptyline: https://fpm.ac.uk/sites/fpm/files/documents/2019-08/Amitriptyline2017.pdf
Nortriptyline: https://www.britishpainsociety.org/static/uploads/resources/files/FPM-Nortriptyline_0.pdf
Duloxetine: https://www.britishpainsociety.org/static/uploads/resources/files/FPM-Duloxetine_0.pdf