Many patients using colexicob, which is sold under the trade name Celebrex, have concerns about safety, and they have good reason. A few weeks after September 2004 when Vioxx was withdrawn from the market, Bextra, a sister drug, was also found to increase the risk of heart disease.
Drugs like Vioxx, Celebrex, and Bextra fall into the class of drugs commonly called NSAIDs or nonsteroidal anti-inflammatory drugs. These drugs belong, in turn, to another subclass called Cox-2 inhibitors or second generation NSAIDs.
Cox-2 inhibitors work by reducing levels of COX-2, an enzyme responsible for inflammation and pain.
The Vioxx Scare
In September, 2004 Merck, the company that manufactures Vioxx, withdrew Vioxx from the market after a clinical trial confirmed that the drug increased risk of heart attack and stroke in patients.
Their decision was based on new data from a clinical trial called APPROVe. The purpose of this trial was to see if Vioxx was effective in preventing the recurrence of colon polyps.
After running 18 months, the trial was halted because patients taking Vioxx had rates of heart attack and stroke double that of those on the placebo. Merck took a $25 billion dollar hit to their market value in one day.
Fast forward several weeks. Both Bextra and Celebrex were under scrutiny for the same effects. Pfizer produces both of these medications.
At this time European regulators were launching a safety investigation into the entire category of Cox-2 inhibitors and Pfizer was considering clinical trials to test the safety of use in the long term.
Not long afterwards, to comply with European regulators, Pfizer took Bextra and Celebrex off the market in Europe.
Celebrex and Colon Cancer Prevention
In December 2004, the National Institute of Health (NIH) suspended a colon cancer prevention trial when the findings implied that Celebrex more than doubled the heart deaths, heart attacks and strokes in people enrolled in the study determining there was concern for Celebrex heart disease safety.
This particular study, called the Adenoma Prevention with Celecoxib (APC) trial, was stopped by an independent Data Safety and Monitoring Board. The APC trial was a study of more than 2,000 people who had a precancerous growth removed and who were randomized for celecoxib to determine if it would prevent the growth of colon cancer.
After the removal of Vioxx from the market in September 2004, more cardiovascular expertise was added to the monitoring committee. Even though the study began in 2000 and was scheduled to be completed Spring 2005, it was immediately suspended in December 2004.
Heart Attack and Stroke
By: Department of Foreign Affairs and Trade
Another ongoing trial, PreSAP, using Celebrex and the same heart measures and safety monitoring board found no increased risk of heart attack or stroke in patients. Other COX-2-selective inhibitors, such as rofecoxib, have appreciably higher myocardial infarction rates than celecoxib.
The opposing findings of both studies was concerning, as was the fact that no previous studies linked Celebrex to heart attacks or stroke.
In April of 2005, Bextra was removed from the market by request of the FDA because the risk of heart attack and stroke appeared to outweigh any benefits of the medication.
The drug company disagreed with the FDA ruling but complied. Bextra was Pfizer’s second leading seller in 2004 at $1.3 billion dollars led only by Celebrex at $3.3 billion dollars.
Currently, concerns for Celebrex heart disease safety has led to increased warnings to physicians and screening of patients who are prescribed the medication.