Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fibromyalgia patients may benefit from cough remedy

20.05.2005


Dextromethorphan, an over-the-counter medication that silences coughs, may help fibromyalgia patients quiet over-reacting nerves that amplify ordinary touches into agony.



A University of Florida study documents, for the first time, that dextromethorphan temporarily reduces the intensity of fibromyalgia "wind-up," a snowballing pain response to minor, repetitive physical contact. The discovery, described in the May issue of The Journal of Pain, also enables researchers to rule out one suspected cause of the phenomenon.

Fibromyalgia is an incurable illness that causes widespread muscle aches, stiffness, fatigue and sleep disturbances, according to the National Fibromyalgia Association. An estimated 10 million Americans suffer from the condition, most of them women. Current treatment strategies include pain medication, exercise, stretching, sleep management and psychological support.


Though the UF study did not establish guidelines for using dextromethorphan clinically, it suggests the drug may eventually be an option for treating fibromyalgia and other conditions involving heightened pain sensitivity, said rheumatology expert Roland Staud, M.D., a UF associate professor of medicine and the study’s principal author.

"I think it’s one piece of the mosaic," Staud said. "We currently have no single therapy in chronic pain that has a big effect. So what this really means for chronic pain patients is that they need to use a whole host of different interventions to decrease the pain they have. And in this, dextromethorphan may have a role in the future."

Dextromethorphan is popular in cold remedies because it elevates the threshold for the coughing reflex but does not cause physical addiction, according to the U.S. Drug Enforcement Administration.

But fibromyalgia patients should not resort to self-medicating by taking cough syrups for pain, Staud cautioned.

"Like every medication, dextromethorphan has side effects," he said. "At high doses, patients can have problems related to memory and confusion."

The underlying cause of fibromyalgia remains unknown, but in the past 25 years substantial progress has been made toward understanding the mechanisms behind specific features of fibromyalgia, Staud said. One is central sensitization, a feature of many chronic pain conditions in which the central nervous system - the brain and spinal cord - somehow magnifies pain signals to abnormally high levels, said Staud, who is affiliated with UF’s McKnight Brain Institute.

Central sensitization is associated with wind-up, a phenomenon in which repeated touches - even handshakes or pats on the back - generate lingering pain that increases with each new contact, he said. A normal form of achy, lingering pain known as secondary pain affects anyone who suffers an injury.

The UF researchers - Staud, neuroscientist Charles Vierck, Ph.D., psychologist Michael Robinson, Ph.D., and Donald Price, Ph.D. - were surprised to learn that dextromethorphan eased fibromyalgia patients’ wind-up pain to the same degree it soothed secondary pain induced in healthy volunteers, Staud said. The results indicate a long-suspected cause of wind-up may not exist.

Previous studies at other institutions had shown that dextromethorphan blocks the action of a chemical messenger called N-methyl-D-aspartate, or NMDA, which relays pain impulses in the spinal cord. Many fibromyalgia researchers have theorized that wind-up is caused by abnormalities in the spinal-cord structures that process NMDA.

The UF results suggest those structures function normally but that pain impulses are more amplified in fibromyalgia than in healthy participants, Staud said.

"This has refocused much of our research now," he said. Future UF studies will attempt to pinpoint where the pain impulses are originating.

In the current study, researchers worked with 14 women with fibromyalgia and 10 women who did not have the disease, using mechanical devices that tapped the participants’ hands repeatedly. One part of the study involved contact with a heated probe, the other used a small rubber-tipped peg. The intensity of the heat or pressure of the stimulation was individually adjusted so that all participants reported feeling the same degree of pain.

Researchers then gave each participant a capsule containing 60 milligrams of dextromethorphan, 90 milligrams of dextromethorphan or a placebo containing none of the drug, and asked them to rate the amount of pain they experienced when the stimulation was repeated.

With the heat stimulus, 90 milligrams of dextromethorphan reduced wind-up pain, but 60 milligrams was no more effective than the placebo. With the pressure stimulus, 90 milligram and 60 milligram doses were equally effective, reducing wind-up pain.

The UF study indicates the need for further research on dextromethorphan, said fibromyalgia expert Laurence Bradley, Ph.D., a professor of medicine with the University of Alabama at Birmingham’s division of clinical rheumatology and immunology.

"This is a topic that’s actually received very little attention so far in the literature," Bradley said. "It would be a disservice to start to recommend that either patients or physicians begin experimenting right away with dextromethorphan, because I think there’s some important questions about how to minimize the side effects with this agent."

Melanie Ross | EurekAlert!
Further information:
http://www.ufl.edu

More articles from Studies and Analyses:

nachricht The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung

nachricht A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>