Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers show COX-2 inhibitors interfere with bone growth, healing

20.11.2002


Researchers at Stanford University Medical Center have found that selective COX-2 inhibitors - a class of medications widely prescribed for painful inflammatory conditions such as osteoarthritis and rheumatoid arthritis - interfere with the healing process after a bone fracture or cementless joint implant surgery.Their findings, published in the November issue of the Journal of Orthopaedic Research, suggest that patients who regularly take COX-2 inhibitors should switch to a different medication, such as acetaminophen or codeine derivatives, following a bone fracture or cementless implant. The study, conducted in rabbits, also suggests that physicians should consider changing prescribing patterns since many doctors commonly prescribe anti-inflammatory drugs including COX-2 inhibitors under the very circumstances in which the drugs should be avoided.



"It’s very common. You break a bone and go to the ER. The doctor sets it in a splint and prescribes one of these anti-inflammatory drugs (including COX-2 inhibitors) for pain," said Stuart Goodman, MD, professor of orthopaedic surgery at the Stanford School of Medicine and lead author of the study. "We now know that could actually delay healing."

The enzyme Cyclooxygenase-2, or COX-2, is produced by the body in response to injury or inflammation. COX-2 inhibitors, including anti-inflammatory medications such as rofecoxib (Vioxx), celecoxib (Celebrex) and others, block production of this enzyme. Goodman’s research shows that COX-2 inhibitors also impede the new bone growth that normally helps heal a fracture or stabilize a joint implant.


Belonging to a class of medications called non-steroidal anti-inflammatory drugs, COX-2 inhibitors were developed in the late 1990s as an alternative to another group of medications called nonspecific NSAIDS, which inhibit the production of COX-2 along with the enzyme Cyclooxygenase-1, or COX-1. Nonspecific NSAIDS, including aspirin, ibuprofen, naproxen and others, often cause stomach irritation and a tendency to bruise easily. COX-2 inhibitors largely avoid these side effects.

Researchers confirmed years ago that nonspecific NSAIDS inhibited bone growth and healing, but the Stanford study is among the first to show that COX-2 inhibitors have the same effect.

In the tibia bone of eight New Zealand white rabbits, Goodman and his team implanted a titanium device called a harvest chamber, which resembles a small screw. The device has a removable, hollow inner core that allows researchers to periodically extract the tissue growing inside. The growth of new bone into the chamber simulates healing of a fracture or joint implant.

Researchers gave the rabbits the following oral treatments for four weeks each: plain water; water with naproxen; plain water again; and sugar-coated pellets of rofecoxib (a COX-2 inhibitor). After each treatment, researchers removed the harvest chamber’s core and extracted the tissue growing inside. After preserving the tissue in liquid nitrogen, the researchers sectioned and processed it with special stains including monoclonal antibodies, allowing them to see how new bone had grown back.

Because a harvest chamber allows new tissue to be extracted multiple times as it grows back, the rabbits served as their own control groups (after consuming plain water) as well as the two experimental groups (after consuming naproxen and rofecoxib). The researchers found that while the tissue in the control group contained 24.8 percent and 29.9 percent new bone growth, the tissue harvested after the rabbits consumed naproxen and rofecoxib contained significantly less - 15.9 percent and 18.5 percent respectively. The difference in new bone growth associated with the two drugs was statistically insignificant; practically speaking, the COX-2 inhibitor impeded new bone growth as much as the nonspecific NSAID.

While acknowledging the limitations of animal research, Goodman said this study "has great applicability to humans, because the healing process is virtually the same" for rabbit and human bones. Goodman is having his own patients avoid COX-2 inhibitors for six weeks after a fracture or joint implant, and he recommends other physicians do the same. "This research has very practical applications."

Goodman said his recommended six-week "time-out" period is an educated guess, because his study didn’t address how long the bone-growth-suppressing effects of COX-2 inhibitors last. To answer that question, Goodman and his colleagues recently began a follow-up study.


Stanford University Medical Center integrates research, medical education and patient care at its three institutions - Stanford University School of Medicine, Stanford Hospital & Clinics and Lucile Packard Children’s Hospital at Stanford. For more information, please visit the Web site of the medical center’s Office of Communication & Public Affairs at http://mednews.stanford.edu.


Sara Selis | EurekAlert!
Further information:
http://med-www.stanford.edu/MedCenter/MedSchool/
http://mednews.stanford.edu

More articles from Health and Medicine:

nachricht Purdue cancer identity technology makes it easier to find a tumor's 'address'
16.11.2018 | Purdue University

nachricht Microgel powder fights infection and helps wounds heal
14.11.2018 | Michigan Technological University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Purdue cancer identity technology makes it easier to find a tumor's 'address'

16.11.2018 | Health and Medicine

Good preparation is half the digestion

16.11.2018 | Life Sciences

Microscope measures muscle weakness

16.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>