Navigation Links
Popular arthritis drug may disrupt heart rhythm, UB research finds
Date:1/24/2008

BUFFALO, N.Y. -- Celebrex, a popular arthritis drug that blocks pain by inhibiting an enzyme known as COX-2, has been shown in laboratory studies to induce arrhythmia, or irregular beating of the heart, via a novel pathway unrelated to its COX-2 inhibition.

University at Buffalo researchers discovered this unexpected finding while conducting basic research on potassium channels.

They found that low concentrations of the drug, corresponding to a standard prescription, reduced the heart rate and induced pronounced arrhythmia in fruit flies and the heart cells of rats.

The drug inhibited the normal passage of potassium ions into and out of heart cells through pores in the cell membrane known as delayed rectifier potassium channels, the study showed.

The adverse effects of drugs like Celebrex and Vioxx based on their selective inhibition of COX-2 currently are a topic of intense discussion in the medical community, said Satpal Singh, Ph.D., associate professor of pharmacology and toxicology in the UB School of Medicine and Biomedical Sciences and senior author on the study. Vioxx was withdrawn from the market in September 2004.

We now have shown an important new effect of Celebrex through a totally different pathway, one that is unrelated to the drugs effect as a pain reducer, Singh said. The adverse effect arising from this unexpected mechanism definitely needs to be studied more closely, because the potassium channels inhibited by the drug are present in heart, brain and many other tissues in the human body.

The research was supported by grants from the National Science Foundation to Singh and Randall D. Shortridge, Ph.D., UB assistant professor of biological sciences, to analyze the basic properties of potassium channels.

Aware that COX-2 inhibitors had been shown to produce cardiovascular side effects, the researchers first tested whether Celebrex would affect the heart in fruit flies, a good animal system for studies on heart in other species, including humans.

When we found an effect on the fly heart, we began looking for the underlying mechanism, said Singh. We searched the fly genome and were surprised to find that these flies dont have cyclooxygenases, the enzymes targeted by Celebrex.

Because the main effect of the drug in our study was induction of arrhythmia, and arrhythmia is often the result of ion-channel dysfunction, continued Singh, we examined the drugs effect on potassium channels and other ion channels in their models and were struck by the strong inhibition of the potassium channels.

The researchers now are examining the underlying molecular mechanisms responsible for the drugs action and its effect on other ion channels that play a prominent role in setting the rhythm of the heart.

We are trying to determine whether the drug binds directly to the channels or to some other molecule, and if it acts by blocking the pore of the channel through which potassium ions travel or by some other mechanism, Singh said.


'/>"/>

Contact: Lois Baker
ljbaker@buffalo.edu
716-645-5000 x1417
University at Buffalo
Source:Eurekalert

Related medicine news :

1. Jan Marini Skin Research Suspends Sales of Popular Eyelash Products
2. Popular osteoporosis drugs triple risk of bone necrosis
3. Climate change, gender differences, health among EurekAlert! 10 Most Popular Stories in 2007
4. Will Lipodissolve Continue to Remain Popular?
5. One-Third of Popular Songs Refer to Substance Abuse
6. Giant Eagle Expands Popular Generic Prescription Program and Now Offers 400 for $4
7. Banco Popular Commits To Make A Difference Day 2007
8. Study Rates Heart Health of Popular Diet Plans
9. HSA Plans Gain Popularity as Premium Costs Rise
10. Exercise Program Eases Arthritis
11. A new view of drugs used to treat rheumatoid arthritis
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/23/2017)... ... May 23, 2017 , ... Therachat , a ... survey in an infographic on the current state of anxiety in support of National ... anxiety, was conducted in April 2017 and benchmarked general anxiety levels as well as ...
(Date:5/22/2017)... ... 2017 , ... The American Academy of Thermology ... and clinical application of medical infrared imaging, has announced two new educational offerings ... services. , The first new educational offering is an online self-directed Physician Member ...
(Date:5/22/2017)... ... May 22, 2017 , ... Dr. Kiya Green, a ... periodontal plastic surgery treatments, including crown lengthening and gum reduction surgery, ... esthetic and functional procedures to help patients improve their oral health, reduce gummy ...
(Date:5/22/2017)... (PRWEB) , ... May 22, 2017 , ... An inventor ... write with a pen. "My wife’s hand was damaged in a firework accident, so ... that helps people with manual problems." , He then designed and created a prototype ...
(Date:5/22/2017)... ... , ... Galena, Alaska, has a population of less than 500 people. But, ... targeted to build a nuclear plant by the TOSHIBA Corporation. , In “The Galena ... describes the journey to get power to his small town, off the electrical grid. ...
Breaking Medicine News(10 mins):
(Date:5/4/2017)... , May 4, 2017  A new ... thermoplastics and other highly-engineered materials, is being launched ... tubing has been developed in recent years to ... therapies and surgical applications. More expensive materials such ... produce microextrusion tubing due to their ability to ...
(Date:5/3/2017)... May 3, 2017  Getinge, a leading global ... quality enhancement and cost efficiency within healthcare and ... of contemporary practice demonstrating that intra-aortic balloon counterpulsation ... critically ill patients. The single-center, retrospective, observational study ... volume MEGA ® 50cc intra-aortic balloon (IAB) ...
(Date:5/2/2017)... May 2, 2017  CIVCO Radiotherapy, the leading ... announced today that Nat Geissel has ... since 2012 and has served as vice president ... president and general manager, and most recently, executive ... am extremely proud of what CIVCO Radiotherapy and ...
Breaking Medicine Technology: