Archive for the ‘Pain’ Category

Written by Honor Whiteman

Anew study has questioned the benefits of opioid painkillers, after finding the drugs might worsen chronic pain rather than ease it.

Study co-leader Prof. Peter Grace, of the University of Colorado at Boulder (CU-Boulder), and colleagues recently published their findings in the Proceedings of the National Academy of Sciences.

Opioids are among the most commonly used painkillers in the United States; almost 250 million opioid prescriptions were written in 2013 – the equivalent to one bottle of pills for every American adult.

Previous studies have suggested opioids – such as codeine, oxycodone, morphine, and fentanyl – are effective pain relievers. They bind to proteins in the brain, spinal cord, and gastrointestinal tract called opioid receptors, reducing pain perception.

Increasing use and abuse of opioids, however, has become a major public health concern in the U.S.; opioid overdoses are responsible for 78 deaths in the country every day.

Now, Prof. Grace and colleagues have questioned whether opioids really work for pain relief, after finding the opioid morphine worsened chronic pain in rats.

Just 5 days of morphine treatment increased chronic pain in rats
According to Prof. Grace, previous studies assessing morphine use have focused on how the drug affects pain in the short term.

With this in mind, the researchers set out to investigate the longer-term effects of morphine use for chronic pain.

For their study, the team assessed two groups of rats with chronic nerve pain. One group was treated with morphine, while the other was not.

Compared with the non-treatment group, the team found that the chronic pain of the morphine group worsened with just 5 days of treatment. What is more, this effect persisted for several months.

“We are showing for the first time that even a brief exposure to opioids can have long-term negative effects on pain,” says Prof. Grace. “We found the treatment was contributing to the problem.”

Another ‘ugly side’ to opioids
According to the authors, the combination of morphine and nerve injury triggered a “cascade” of glial cell signaling, which increased chronic pain.

Glial cells are the “immune cells” of the central nervous system, which support and insulate nerve cells and aid nerve injury recovery.

They found that this cascade activated signaling from a protein called interleukin-1beta (IL-1b), which led to overactivity of nerve cells in the brain and spinal cord that respond to pain. This process can increase and prolong pain.

The researchers say their findings have important implications for individuals with chronic pain – a condition that is estimated to affect around 100 million Americans.

“The implications for people taking opioids like morphine, oxycodone and methadone are great, since we show the short-term decision to take such opioids can have devastating consequences of making pain worse and longer lasting. This is a very ugly side to opioids that had not been recognized before.”

Study co-leader Prof. Linda Watkins, CU-Boulder

It is not all bad news, however. The researchers found they were able to reverse morphine’s pain-increasing effect using a technique called “designer receptor exclusively activated by designer drugs” (DREADD), which involves the use of a targeted drug that stops glial cell receptors from recognizing opioids.

“Importantly, we’ve also been able to block the two main receptors involved in this immune response, including Toll-Like receptor 4 (TLR4) and another one called P2X7R, which have both been separately implicated in chronic pain before,” notes Prof. Grace.

“By blocking these receptors, we’re preventing the immune response from kicking in, enabling the painkilling benefits of morphine to be delivered without resulting in further chronic pain.”

He adds that drugs that can block such receptors are currently in development, but it is likely to be at least another 5 years before they are available for clinical use.

http://www.medicalnewstoday.com/articles/310645.php

Thanks to Kebmnodee for bringing this to the attention of the It’s Interesting community.

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mindfulness-meditation

By Andrew M. Seaman

Mindfulness meditation may be useful in battles against anxiety, depression and pain, according to a fresh look at past research.

Using data from 47 earlier studies, researchers found moderate evidence to support the use of mindfulness meditation to treat those conditions. Meditation didn’t seem to affect mood, sleep or substance use.

“Many people have the idea that meditation means just sitting quietly and doing nothing,” wrote Dr. Madhav Goyal in an email to Reuters Health. “That is not true. It is an active training of the mind to increase awareness, and different meditation programs approach this in different ways.”

Goyal led the study at The Johns Hopkins University in Baltimore.

He and his colleagues write in JAMA Internal Medicine that meditation techniques emphasize mindfulness and concentration.

So-called mindfulness meditation is aimed at allowing the mind to pay attention to whatever thoughts enter it, such as sounds in the environment, without becoming too focused. Mantra meditation, on the other hand, involves focusing concentration on a particular word or sound.

Approximately 9 percent of people in the U.S. reported meditating in 2007, according to the National Institutes of Health. About 1 percent said they use meditation as some sort of treatment or medicine.

For the new report, the researchers searched several electronic databases that catalog medical research for trials that randomly assigned people with a certain condition – such as anxiety, pain or depression – to do meditation or another activity. These randomized controlled trials are considered the gold standard of medical research.

The researchers found 47 studies with over 3,500 participants that met their criteria.

After combining the data, Goyal said his team found between a 5 and 10 percent improvement in anxiety symptoms among people who took part in mindfulness meditation, compared to those who did another activity.

There was also about a 10 to 20 percent improvement in symptoms of depression among those who practiced mindfulness meditation, compared to the other group.

“This is similar to the effects that other studies have found for the use of antidepressants in similar populations,” Goyal said.

Mindfulness meditation was also tied to reduced pain. But Goyal said it’s hard to know what kind of pain may be most affected by meditation.

The benefits of meditation didn’t surpass what is typically associated with other treatments, such as drugs and exercise, for those conditions.

“As with many therapies, we try to get a moderate level of confidence that the therapy works before we prescribe it,” Goyal said. “If we have a high level of confidence, it is much better.”

But he noted that the researchers didn’t find anything more than moderate evidence of benefit from meditation for anxiety, depression and pain.

There was some suggestion that meditation may help improve stress and overall mental health, but the evidence supporting those findings was of low quality.

There was no clear evidence that meditation could influence positive mood, attention, substance use, eating habits, sleep or weight.

“Clinicians should be prepared to talk with their patients about the role that meditation programs could have in addressing psychological stress, particularly when symptoms are mild,” Goyal said.

Dr. Allan Goroll, who wrote an editorial accompanying the new study, told Reuters Health the analysis is an example of an area of much-needed scientific study, because many people make treatment decisions based on beliefs – not data.

“That is particularly the case with alternative and complimentary approaches to treating medical problems,” he said. “It ranges from taking vitamins to undergoing particular procedures for which the scientific evidence is very slim but people’s beliefs are very great.”

Goroll is professor at Harvard Medical School and Massachusetts General Hospital in Boston.

Goyal said people should remember that meditation was not conceived to treat any particular health problem.

“Rather, it is a path we travel on to increase our awareness and gain insight into our lives,” he wrote. “The best reason to meditate is to gain this insight. Improvements in health conditions are really a side benefit, and it’s best to think of them that way.”

SOURCE: bit.ly/WiwDtv JAMA Internal Medicine, online January 6, 2014.

 

A painkiller as powerful as morphine, but without most of the side-effects, has been found in the deadly venom of the black mamba, say French scientists.

The predator, which uses neurotoxins to paralyse and kill small animals, is one of the fastest and most dangerous snakes in Africa.

However, tests on mice, reported in the journal Nature, showed its venom also contained a potent painkiller.

They admit to being completely baffled about why the mamba would produce it.

The researchers looked at venom from 50 species before they found the black mamba’s pain-killing proteins – called mambalgins.

Dr Eric Lingueglia, from the Institute of Molecular and Cellular Pharmacology near Nice, told the BBC: “When it was tested in mice, the analgesia was as strong as morphine, but you don’t have most of the side-effects.”

Morphine acts on the opioid pathway in the brain. It can cut pain, but it is also addictive and causes headaches, difficulty thinking, vomiting and muscle twitching. The researchers say mambalgins tackle pain through a completely different route, which should produce few side-effects.

He said the way pain worked was very similar in mice and people, so he hoped to develop painkillers that could be used in the clinic. Tests on human cells in the laboratory have also showed the mambalgins have similar chemical effects in people.

But he added: “It is the very first stage, of course, and it is difficult to tell if it will be a painkiller in humans or not. A lot more work still needs to be done in animals.”

Dr Nicholas Casewell, an expert in snake venom at the Liverpool School of Tropical Medicine, has recently highlighted the potential of venom as a drug source.

Commenting on this study he said: “It’s very exciting, it’s a really great example of drugs from venom, we’re talking about an entirely new class of analgesics.”

Dr Lingueglia said it was “really surprising” that black mamba venom would contain such a powerful painkiller.

Dr Casewell agreed that it was “really, really odd”. He suggested the analgesic effect may work in combination “with other toxins that prevent the prey from getting away” or may just affect different animals, such as birds, differently to mice.

The Royal Pharmaceutical Society’s Dr Roger Knaggs said: “We are witnessing the discovery of a novel mechanism of action which is not a feature of any existing painkillers.”

He cautioned that the mambalgins worked by injections into the spine so would need “significant development” before they could be used in people.

http://www.bbc.co.uk/news/health-19812064

Thanks to Kebmodee for bringing this to the It’s Interesting community.

If your hand hurts, simply cross your arms to confuse your brain and reduce the perceived pain intensity. 

Researchers believe this happens because of conflicting information between two of the brain’s maps: the one for your body and the one for external space.

Since the left hand typically performs actions on the left side of space (and the right hand performs on the right side), these two maps work together to create powerful impulses in response to stimuli. When the arms are crossed, however, the two maps are mismatched and information processing becomes weaker — resulting in less pain.

http://psychcentral.com/news/2011/05/22/crossing-arms-confuses-brain-but-relieves-hand-pain/26390.html