The 'happy pill' that eases the agony of arthritis

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UPDATED:

07:26 GMT, 24 April 2012


Getting moving again: Doing the Charleston could become a lot easier thanks to a 'happy pill' that is tipped to ease the pain of arthritis

Getting moving again: Doing the Charleston could become a lot easier thanks to a 'happy pill' that is tipped to ease the pain of arthritis

A ‘happy pill’ that costs less than a pound a day could help ease osteoarthritis pain.

The drug, called duloxetine, halved pain levels in patients with damaged knees compared to a dummy pill, according to a recent report in the Journal of Rheumatology.

Duloxetine, which costs around 22 for a month’s supply, was originally developed as an antidepressant and acts on serotonin and noradrenalin, chemical messengers in the brain and spinal cord.

However, emerging evidence suggests the drug can also dampen down pain, possibly by blocking signals from reaching the brain.

An
estimated eight million people in Britain have some degree of
osteo-arthritis, which causes the destruction of cartilage — the body’s
built-in shock absorber.

As
the body ages, major joints such as the hips, knees and wrists suffer
wear and tear; the cartilage then wears away, leaving the bones to rub
together and disintegrate, causing swelling and pain.

There
is no cure and many sufferers rely on anti-inflammatory painkillers to
ease their suffering. While these help, they can damage the stomach if
used for a long time.

In more severe cases, patients may be offered steroid injections to dampen down inflammation. Around 60,000 people a year in Britain end up needing a knee replacement because their joints are too badly eroded.

In the new U.S. study, researchers at the University of Maryland gave one group of osteoarthritis patients a daily dose of duloxetine for 13 weeks, while another group had an identical looking placebo pill.

Help at hand The drug could treat an estimated eight million people in Britain who have some degree of osteo-arthritis, which causes the destruction of cartilage

Help at hand The drug could treat an estimated eight million people in Britain who have some degree of osteo-arthritis, which causes the destruction of cartilage

The duloxetine group experienced a drop in pain levels by between a third and a half compared to those on the dummy tablet.

The mechanism by which the drug reduces
pain is poorly understood. One theory is that it boosts levels of
serotonin and noradrenalin, which dilute the strength of the pain
signals that travel from the spinal cord to the brain.

GLOVE COULD TRANSFORM DIAGNOSIS OF ARTHRITIS

Meanwhile, scientists have developed a high-tech glove that measures joint movements in the hand.

This
could transform the diagnosis of rheumatoid arthritis, which occurs
when the body’s immune system mistakenly attacks cartilage in the
joints.

The computerised
glove, which has been developed at the University of Ulster, is packed
with tiny sensors that monitor mobility of the wrist, thumb and finger
joints.

Patients will wear
the glove at home so doctors can compile a picture of how severe joint
stiffness is at different times of the day.

Rheumatoid
arthritis affects 350,000 people in Britain. Doctors rely on X-rays and
patients self-reporting to assess the severity of joint stiffness.

The
degree of stiffness can affect which drugs are prescribed, but the
quality of diagnosis can vary from one clinician to another.

This could potentially allow the disease to progress and do irreversible damage to joints.

The
high-tech glove downloads data on to a doctor’s computer to create a
3-D image of the patient’s hand movements, enabling them to get the
correct drug therapy much sooner.

A prototype of the glove is being tested on patients with rheumatoid arthritis at Altnagelvin Hospital in Londonderry.

Duloxetine is also used to treat other types of pain. A recent report from the highly respected Cochrane Library found that it can tackle diabetic neuropathic pain, which occurs when high blood sugar levels cause nerve damage.

This causes a burning or stabbing sensation in various parts of the body.

Studies show that duloxetine can reduce this by 50 per cent — one-and-a-half times more than a placebo pill.

However, the experts caution that around one in six people stop taking the pill due to the side-effects, which include nausea and dizziness.

Antidepressant drugs have also been found to work for other types of chronic pain, such as the discomfort caused by shingles. This burning pain, often found on the face, is thought to be caused by nerve damage, and tricyclic antidepressant drugs, such as amitriptyline, can be effective.

These work on chemical transmitters in the brain and block unpleasant pain signals coming from peripheral nerves in the skin.

The dose is usually slowly increased from a low level, such as 10mg, and then increased to 25mg or 75mg.

However, a common problem is that a patient usually doesn’t see a reduction in pain from the pills until after three or four weeks of taking them, and so too many people stop and give up too soon.

Commenting on the use of the duloxetine for knee arthritis, a spokeswoman for the charity Arthritis Research UK said: ‘We know antidepressants have a propensity to modify back pain in particular, but it’s not clear if they work well in peripheral joint osteoarthritis.

'There have been a number of trials of this drug, but they have shown mixed results.’