Dementia Centred

By Prof. Emma Reynish

February 2nd, 2017

Treatment of pain in people with dementia

The wear and tear of everyday life gradually has an impact on our bodies. The likelihood of experiencing pain increases with advancing years due to the degenerative changes caused by the wear and tear in joints such as knees and hips and in the back. Degenerative joint disease or osteoarthritis can affect us all as we age and people affected by dementia are not excluded. Osteoarthritis is the most common cause of pain but other illnesses (such as diabetes and constipation) have their own pain manifestations.

The way we experience pain can be very personal and is likely to be different in all individuals. Chronic pain (that affects us day in, day out) is as likely to manifest as fatigue, frustration and a lack of wellbeing as it is as direct pain, which can be pinpointed to one location. Additionally pain due to joint disease in one area can be felt in a completely different but associated place in the body e.g. osteoarthritis of the hip can be experienced as knee pain. An individual’s experience of pain is also complicated by the nature of the underlying abnormality that causes the pain. For example, general wear and tear of the bones in the back can lead to degeneration of the bones which lose their form and may start to rub on the nerves that originate in the spinal cord causing “neuropathic” or nerve pain. This can result in pain that may be described as shooting pain or throbbing pain.

People with dementia will experience all these types of pain as frequently as the general population. Their dementia, however, may affect the way that each individual experiences and manifests the pain. It may be difficult to recognise the discomfort experienced and then communicate that it is pain. Someone with dementia, who experiences pain may be more prone to the associated feelings of fatigue, frustration and a lack of wellbeing. Their experience of pain may only be perceived as a change in everyday routine (such as change in sleep pattern) by people around them. In cases of more debilitating pain feelings of frustration may be exhibited by a change in behaviour or new distressed behaviours.

From a care professional’s point of view the assessment of pain in someone with dementia must include discussions with carers, family and friends who will be able to report on any recent changes in habits or behaviour.

Common causes of pain in people with dementia include:

  • osteoarthritis – general wear and tear of bones especially at joints e.g. hands/knees and hips
  • osteoporosis – thinning of the bones which may results in crush fractures in the bones, in the spine or an increased risk of broken bones following minor trauma
  • fractured bones – especially the hip after a fall
  • constipation
  • urinary retention – can be associated with urine infection and/or constipation
  • peripheral neuropathy – most commonly seen in patients with diabetes
  • peripheral vascular disease – resulting in leg pain when walking or chronic ischemic pain of the toes

Because of the frequency of these diverse types of pain in the older population, people with dementia will frequently experience some sort of pain. If there is a suspicion that someone with dementia is experiencing pain then treatment should be tried. This low threshold for a trial of treatment should however be coupled with an overriding principle that the treatment tried must not cause further harm.

The first step should therefore be a trial of regular paracetamol tablets. This medication has few side effects and in a study (Husebo et al., 2011) patients with dementia who were not able to complain of pain were shown to exhibit a reduction in distressed behaviour when treated for pain.

Stronger pain killing medications beyond this first step all have the potential to cause serious side effects in people with dementia and medical advice should be sought if these further treatment steps are needed. The potential side effects can be divided into those that affect both people with and without dementia and those that are specific to people with dementia.

Stronger painkillers generally have some opiate whether weak such as codeine or stronger such as morphine. Common side effects include constipation/nausea and drowsiness and these should be observed for and treated in anyone who is started on opiate related painkillers.

Other side effects can be related to reduction in kidney function that is often seen in older individuals. Some opiate painkillers rely on being excreted via the kidneys and tend to build up in the body and cause worsening side effects “opiate toxicity” if a person’s kidney function is impaired, even temporarily due to an infection.

Side effects that are specific to people with dementia are associated with the cognitive effects of medications. Opiate medications can cause delirium (an increase in confusion). When coupled with a reduction in kidney function increased confusion, or delirium, can come about with small doses of weak opiates such as codeine or co-codamol. Newer “opiate like” medicines do not rely on the kidneys for their metabolism and seem to cause fewer problems with delirium when used as painkillers for people with dementia.

 Other side effects that tend to reduce an individual’s cognitive function and are therefore specific to people with dementia can be associated with medicines that have an “anticholinergic burden” ( Mulsant et al., 2003) . This means that alongside their painkilling properties they inadvertently reduce the action of one of the chemicals that transmits signals in the brain. This neuro-transmitting chemical is important for memory functioning, and the majority of current treatments for dementia are “pro-cholinergic” or increase the action of this chemical. Painkilling medicine that fall into this category are often used for the treatment of nerve pain. They can be very effective but in people with dementia getting the correct dose of these tablets is fraught with difficulty for doctors who need to balance the positive painkilling action with the detrimental effect that the medicine can have on someone’s memory.

Pain is common in people with dementia because conditions that cause pain are frequent and are often associated with increasing age. The way a person with dementia shows pain can be different in all individuals, with direct complaints of pain often absent and changes in sleep pattern or behaviour being possible. Because pain is so common, simple treatment with regular paracetamol in the first instance should be tried even when the suspicion of pain is low. Stronger treatments should be given careful consideration; side effects are common and unpredictable and can cause a deterioration in someone’s memory and increased confusion. The overriding principle that the treatment tried must not cause further harm, should be adhered to at all time.

References:

Rodger, K.T. [et al.] (2015) Expert opinion on the management of pain in hospitalised older patients with cognitive impairment: a mixed methods analysis of a national survey. BMC Geriatrics 15:56.

Husebo, B. [et al.] (2011) Efficacy of treating pain to reduce behavioural disturbances in residents of nursing homes with dementia: cluster randomised clinical trial BMJ 2011;343:d4065

Mulsant, B.H. [et al.] (2003) Serum anticholinergic activity in a community-based sample of older adults: relationship with cognitive performance Archives of general psychiatry 60(2), 198-203

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