Managing the Pain of Rheumatoid Arthritis

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Medical Info - RA & You

" Managing the Pain of Rheumatoid Arthritis "

Author: Dr Philip Conaghan (Senior Lecturer in Rheumatology & Consultant

Rheumatologist University of Leeds & Leeds General Infirmary, Leeds UK)

Pain is an extremely personal experience. While this review will try to

explain some simple mechanisms for pain and the current treatments for

pain in rheumatoid arthritis (Rheumatoid Arthritis) patients, such an

overview represents a view based on an understanding of the

evidence-based literature on current Rheumatoid Arthritis therapies and

an individual rheumatologist's experience - it cannot fully explain

every individual patient's pain problems. All pain that is present for a

reasonable length of time, no matter what the underlying cause, can be

associated with poor sleep patterns and depressed mood. The stress

associated with Rheumatoid Arthritis-related job loss or relationship

problems all impact on how we cope with pain. Mechanistically, pain

involves not only the nerves at the site of pain but the nerve pathways

leading to the brain and special pain pathways within the brain itself.

Very simply, pain is a complex phenomenon.

Why do people with rheumatoid arthritis get pain?

If you are reading this article then you probably already know a little

about Rheumatoid Arthritis and that it is a chronic inflammatory

disease. The disease process seems to start in the joint lining tissue

or synovium and this tissue becomes very inflamed - this is termed

synovitis. It is widely assumed that synovitis, together with all the

inflammatory chemicals and inflammation of local nerve fibres, is the

cause of pain in Rheumatoid Arthritis.

It is most important though to realise that sufferers of Rheumatoid

Arthritis will have often have pain for a variety of reasons. It is

helpful for an individual to learn something about what is causing their

individual pain. Early on in the disease process much of the pain

probably arises from Rheumatoid Arthritis synovitis. The simplest

evidence suggesting that treatment of inflammation relieves pain is seen

in the experience of many patients who have had a corticosteroid

injection into an inflamed joint, with subsequent quick-onset relief of

pain.

However some other important factors cause pain in a lot of Rheumatoid

Arthritis patients. After having Rheumatoid Arthritis for even a few

months, sufferers will be aware that they have a lot of muscle wasting:

in the forearms if they have a lot of arthritis in their hand joints or

in the thighs if they have a lot of knee problems (or both!). These weak

muscles mean excess strain is taken through adjacent joints and this

strain leads to pain at areas where tendons are attached to the joints.

As well, with even the best of modern therapies, prolonged inflammation

in individual joints will lead to some joint damage and a process of

osteoarthritis (called secondary osteoarthritis because it happens as a

result of the Rheumatoid Arthritis). Osteoarthritis refers to the

process of permanent cartilage and adjacent bone damage (usually

associated with ageing and injured joints); the mechanisms of pain in

osteoarthritis are probably different from those of Rheumatoid Arthritis

pain.

So in summary, after a variable length of time but certainly after a few

years, most patients with Rheumatoid Arthritis will have pain relating

to any or all of:

Active inflammation or synovitis and mechanical factors:

Mechanical joint pain due to muscle weakness, and

Secondary osteoarthritis.

This is why it is unusual to find that just one therapy is completely

effective at relieving any one person's pain. It is also important to

realise that the cause of pain may differ between joints within an

individual patient.

How do we tell what is the cause of joint pain in an Rheumatoid

Arthritis patient?

When a rheumatologist sees a patient with Rheumatoid Arthritis and pain

is their primary complaint, the first step is often to assess how active

the synovitis or inflammation component of disease is, since treatment

of this is important not only to prevent pain but also to prevent

further joint damage. Inflammation is often associated with prolonged

morning stiffness, whereas an osteoarthritic joint will be painful and

stiff for only a few minutes on waking and then get worse with usage

over the day.

The rheumatologist will also assess the degree of inflammation by

measures such as the number of tender and swollen joints and blood tests

that indicate general inflammation levels (called the erythrocyte

sedimentation rate or ESR and the C-reactive protein or CRP).

It is often difficult in patients with long-standing disease to

determine whether persistent Rheumatoid Arthritis synovitis or

osteoarthritis is the problem in any one joint, and this may be

especially difficult in large joints such as the knee. As stated above,

often more than one problem is present.

What can be done for Rheumatoid Arthritis pain?

It should be stressed that adequate suppression of inflammation is the

usual first step in managing Rheumatoid Arthritis pain. However, since

the pain in Rheumatoid Arthritis may have multiple causes, a combination

of treatments is often required. Most patients who have Rheumatoid

Arthritis will be familiar with many of the treatments listed below:

A. Non-drug therapy of pain

Resting inflamed joints is a well-tried method for assisting in pain

relief and the use of splints on the wrist is a commonly used tool to

reduce pain in that site. The use of a walking stick helps take weight

off an affected knee or hip joint. The use of thick, cushioned-soled

shoes and arch-supports can help foot pain (or even getting shoes that

fit a rheumatoid-damaged foot!).

Strong muscles take weight off painful joints. Simple forearm exercises

may help reduce hand pain whereas straight leg raising (quadriceps)

exercises will help reduce knee pain. Some patients with Rheumatoid

Arthritis will of course find it difficult to exercise because of the

malaise and lethargy resulting from the inflammatory chemicals produced

by their inflamed joints. However for many patients, gentle exercise

will be beneficial; for example, walking laps in a swimming pool allows

for muscle strengthening while reducing load through an inflamed or

damaged joint.

If joint damage is severe then sometimes the only therapy that will help

relieve pain significantly is to surgically replace the joint. Joint

replacement is successful treatment for severe arthritis involving the

knee and hip, but can also sometimes be used in the shoulder and small

joints of the hand.

B. Drug therapy of Rheumatoid Arthritis pain

The usual drugs used for treating the inflammation of Rheumatoid

Arthritis are non-steroidal anti-inflammatory drugs (NSAIDs), disease

modifying drugs (such as methotrexate or sulphasalazine and more

recently the biologics including those called anti-TNF therapies) and

corticosteroids (which may be used orally as prednisolone or via joint

injections).

Most studies of Rheumatoid Arthritis focus on anti-inflammation

therapies, and in large studies it is not always practical to work out

how much of an individual's pain is due to mechanical factors. The

evidence for treating the mechanical causes of joint pain is essentially

that derived from osteoarthritis studies, and there are few such

long-term studies.

It is uncommon to find one drug that relieves all arthritis pain for any

one person. The pharmacological agents commonly used to treat

musculoskeletal pain, including that associated with Rheumatoid

Arthritis, are:

Paracetamol

This is the commonest drug used for joint pains. It is generally safe in

doses up to 4 grams daily. Very high doses or use together with heavy

alcohol intake can lead to liver damage.

NSAIDs

These agents may be used orally or as topical preparations and act not

only as anti-inflammatory agents but also as analgesics. They have

typical quick onset of action, need to be taken at least once a day and

their analgesic effect lasts for a number of hours, depending on the

particular drug used. The major side effects of NSAIDs include dyspepsia

(upper abdominal burning or bloating sensation, often described as

indigestion) and very uncommonly stomach ulcers and bleeding. All NSAIDs

may cause aggravation of blood pressure and ankle swelling (by causing

fluid retention).

Opioid analgesics

Codeine-containing drugs (known as weak opioids - examples include

paracetamol/codeine combinations, dihydrocodeine and tramadol) are the

commonest used in this category but stronger painkillers, (eg fentanyl

in topical patches) have been used in patients with moderate to severe

musculoskeletal pain. Unlike paracetamol and NSAIDs, which work in the

joints themselves, opiate-derived drugs seem to work in the central

nervous system. The term " opiates " is often associated with fears of

addiction. However the vast majority of patients using such drugs for

chronic pain never become addicted. Doses of these drugs are usually

increased slowly to get a balance between pain reduction and unwanted

side-effects. The common side-effects of this class of drugs are

constipation, nausea and drowsiness. High fibre diet and laxatives may

be useful if the drugs are helping pain but causing constipation and

some opioids are less constipating than others. Drowsiness may be

helpful if the drugs are used at night in people with sleep disturbance

due to pain, but care must be taken during daytime activities such as

driving (if you are on stronger analgesics you should check with your

doctor to see if the drug is licensed for people who want to drive).

Combinations of the above drugs may be useful in many patients since the

drugs work in different ways. It is common for patients with chronic

arthritis pain to be using both a NSAID and paracetamol or NSAID and

paracetamol/codeine combination tablets.

Certain antidepressants may help pain, not only through analgesic effect

but also through positive effects on sleep and mood.

Summary

Pain is complex and the causes of pain in Rheumatoid Arthritis may be

due to inflammation or related mechanical factors. Hopefully this

article has provided some information on the cause of Rheumatoid

Arthritis joint pain and an understanding that inflammation control,

analgesics and non-drug therapies are all important in helping reduce

the burden of pain.

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