Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Chemical imbalance may explain painkiller’s cardiac danger

14.09.2005


The increased rate of cardiovascular complications in patients taking the cox-2 inhibitor painkiller rofecoxib (Vioxx) may result from a chemical imbalance, according to an animal study in the September Cell Metabolism. The findings suggest that low-dose aspirin might prevent the cardiac damage of such drugs and might also lead to the development of new anti-inflammatory drugs without the adverse side effects, the researchers said.



Earlier studies in humans have found that cox-2 inhibitors cause a decline in prostacyclin, a chemical that normally keeps blood vessels open and prevents blood clots. That drop occurs without a change in concentration of thromboxane, a related agent that constricts vessels and promotes clot formation.

The new study by researchers at Duke University and Durham VA Medical Centers found that, in mice prone to high blood pressure, an inability to respond to prostacyclin led to cardiac complications, including hypertension, enlarged hearts and severe scarring of the heart. Moreover, they showed, unrestrained action of thromboxane in the absence of prostacyclin accentuated the intensity of cardiac damage caused by the high blood pressure.


"The current results suggest that such a chemical imbalance in patients taking selective cox-2 inhibitor painkillers may present a cardiovascular hazard--particularly for people already predisposed to high blood pressure," said study author Thomas Coffman.

"Hypertension is the most common cardiovascular complication associated with cox-2 inhibition, yet not everybody who takes the drugs develops high blood pressure," he continued. "The mice appear to have characteristics similar to the subset of patients who are prone to experience this side effect."

Cox-2 inhibitors and other nonsteroidal, anti-inflammatory drugs (NSAIDs)--including aspirin and ibuprofen--all reduce inflammation and pain by blocking the function of cyclo-oxygenases, also known as cox enzymes. The cox enzymes, cox-1 and cox-2, normally produce prostanoids--a family of related chemicals, including prostaglandins and thromboxanes, with many important functions throughout the body.

Prostaglandins produced by both enzymes promote inflammation, pain, and fever, while others made by cox-1 protect the stomach from the damaging effects of acid. The cox-1 and cox-2 enzymes, respectively, also produce thromboxane and prostacyclin.

Traditional NSAIDs relieve pain and inflammation by simultaneously blocking the function of both cox enzymes, Coffman explained. In contrast, rofecoxib and other cox-2 inhibitors selectively limit cox-2, thereby avoiding the gastrointestinal complications of over-the-counter NSAIDs.

A 2004 study, however, found an early rise in blood pressure and an increased rate of heart attack and stroke in patients treated with rofecoxib for more than 18 months. Last year, the manufacturer withdrew the drug from the market.

The current findings may lead to new drugs that avoid the pitfalls of both traditional NSAIDs and existing cox-2 inhibitors, the researchers said.

"Ultimately, through the dissection of these intricate pathways, it may be possible to identify drugs that provide all the therapeutic effects of NSAIDs and cox-2-selective inhibitors but lack their adverse side effects," added Matthew Breyer of Vanderbilt University Medical School in an accompanying preview. "Until that time, one can only marvel at the combination of therapeutic and cardioprotective effects of nature’s own compound, salicylate, and its chemically modified derivative, aspirin."

Heidi Hardman | EurekAlert!
Further information:
http://www.cellmetabolism.org

More articles from Life Sciences:

nachricht Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz

nachricht Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>