Featured Research

from universities, journals, and other organizations

Chemical Imbalance May Explain Painkiller's Cardiac Danger

Date:
September 19, 2005
Source:
Cell Press
Summary:
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.

The increased rate of cardiovascular complications in patients takingthe cox-2 inhibitor painkiller rofecoxib (Vioxx) may result from achemical imbalance, according to an animal study in the September CellMetabolism. The findings suggest that low-dose aspirin might preventthe cardiac damage of such drugs and might also lead to the developmentof new anti-inflammatory drugs without the adverse side effects, theresearchers said.

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

The new study by researchers at Duke University and Durham VAMedical Centers found that, in mice prone to high blood pressure, aninability to respond to prostacyclin led to cardiac complications,including hypertension, enlarged hearts and severe scarring of theheart. Moreover, they showed, unrestrained action of thromboxane in theabsence of prostacyclin accentuated the intensity of cardiac damagecaused by the high blood pressure.

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

"Hypertension is the most common cardiovascular complicationassociated with cox-2 inhibition, yet not everybody who takes the drugsdevelops high blood pressure," he continued. "The mice appear to havecharacteristics similar to the subset of patients who are prone toexperience this side effect."

Cox-2 inhibitors and other nonsteroidal, anti-inflammatorydrugs (NSAIDs)--including aspirin and ibuprofen--all reduceinflammation and pain by blocking the function of cyclo-oxygenases,also known as cox enzymes. The cox enzymes, cox-1 and cox-2, normallyproduce prostanoids--a family of related chemicals, includingprostaglandins and thromboxanes, with many important functionsthroughout the body.

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

Traditional NSAIDs relieve pain and inflammation bysimultaneously blocking the function of both cox enzymes, Coffmanexplained. In contrast, rofecoxib and other cox-2 inhibitorsselectively limit cox-2, thereby avoiding the gastrointestinalcomplications of over-the-counter NSAIDs.

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

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

"Ultimately, through the dissection of these intricatepathways, it may be possible to identify drugs that provide all thetherapeutic effects of NSAIDs and cox-2-selective inhibitors but lacktheir adverse side effects," added Matthew Breyer of VanderbiltUniversity Medical School in an accompanying preview. "Until that time,one can only marvel at the combination of therapeutic andcardioprotective effects of nature's own compound, salicylate, and itschemically modified derivative, aspirin."

###

The researchers include Helene Francois, Krairerk Athirakul, DavidHowell, Rajesh Dash, Lan Mao, Howard A. Rockman, and Thomas M. Coffmanof Duke University and Durham VA Medical Centers, Durham, NC; Garret A.FitzGerald of the University of Pennsylvania, Philadelphia, PA; andHyung-Suk Kim and Beverly H. Koller of the University of NorthCarolina, Chapel Hill, NC. This work was supported by funding from theMedical Research Service of the Veterans Administration and by NationalInstitutes of Health (B.H.K. and T.M.C.).

Francois et al.: "Prostacyclin Protects Against Elevated BloodPressure And Cardiac Fibrosis" Publishing in Cell Metabolism, Vol. 2,September 2005, pages 201-207. DOI 10.1016/j.cmet.2005.08.005 www.cellmetabolism.org.


Story Source:

The above story is based on materials provided by Cell Press. Note: Materials may be edited for content and length.


Cite This Page:

Cell Press. "Chemical Imbalance May Explain Painkiller's Cardiac Danger." ScienceDaily. ScienceDaily, 19 September 2005. <www.sciencedaily.com/releases/2005/09/050918132504.htm>.
Cell Press. (2005, September 19). Chemical Imbalance May Explain Painkiller's Cardiac Danger. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2005/09/050918132504.htm
Cell Press. "Chemical Imbalance May Explain Painkiller's Cardiac Danger." ScienceDaily. www.sciencedaily.com/releases/2005/09/050918132504.htm (accessed July 31, 2014).

Share This




More Health & Medicine News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

House Republicans Vote to Sue Obama Over Healthcare Law

House Republicans Vote to Sue Obama Over Healthcare Law

Reuters - US Online Video (July 31, 2014) The Republican-led House of Representatives votes to sue President Obama, accusing him of overstepping his executive authority in making changes to the Affordable Care Act. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Despite Health Questions, E-Cigs Are Beneficial: Study

Despite Health Questions, E-Cigs Are Beneficial: Study

Newsy (July 31, 2014) Citing 81 previous studies, new research out of London suggests the benefits of smoking e-cigarettes instead of regular ones outweighs the risks. Video provided by Newsy
Powered by NewsLook.com
Dangerous Bacteria Kills One in Florida

Dangerous Bacteria Kills One in Florida

AP (July 31, 2014) Sarasota County, Florida health officials have issued a warning against eating raw oysters and exposing open wounds to coastal and inland waters after a dangerous bacteria killed one person and made another sick. (July 31) Video provided by AP
Powered by NewsLook.com
Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins