Celebrex Heart Attack: Risk Factors Remain, and so does The Drug

Chicago, ILFirst the good news—it appears that Celebrex taken at lower doses pose less of a risk for heart attack, than when Celebrex is taken at a higher dose. The bad news? There is a risk for heart attack either way.

The COX-2 selective inhibitor manufactured by Pfizer Pharmacia has long been suspected of having links to cardiovascular events, and has long been studied in an effort to conclusively determine just what those risk levels are.

The latest data, presented this week at the annual meeting of the American College of Cardiology, comes from a study funded by the National Cancer Institute where data from six studies involving 8,000 patients comparing Celebrex against a placebo was pooled.

The study concluded that patients taking the highest dose of Celebrex, reported as 400 milligrams twice daily, presented three times the risk for myocardial infarction, stroke and other cardiovascular problems. Those taking a lower dose, identified as either 200 milligrams twice daily or 400 milligrams once daily, carried about a 10 percent chance of cardiovascular complication, against patients who didn't take Celebrex at all.

It was also determined that patients with high risk factors for cardiovascular complication in general, should only use Celebrex as a last resort—and that the higher the cardiovascular risk factor in general, the higher the risk generated by Celebrex.

It has been reported that the American Heart Association has long included in its guidelines the recommendation that Celebrex should be taken by patients with existing heart risks only as a last resort, and only for the shortest period of time.

Celebrex is a pain medication commonly taken to ease the symptoms of osteoarthritis. Interestingly enough, the most common dose for the treatment of arthritis is 200 milligrams per day—however there is no conclusive data indicating whether or not Celebrex, at that dose, is safe.

That is about to change, but we'll have to wait for it. A study dubbed PRECISION is headed up by noted cardiologist and critic Steven Nissen. PRECISION will compare the most common Celebrex dose of 200 milligrams once daily, against similar doses of ibuprofen and naproxen in patients with either rheumatoid arthritis or osteoarthritis, together with high risk for cardiovascular events. The results will be compared across 20,000 participants and are expected to be available in three years.

Until then, we can only assume that 200 milligrams of Celebrex once per day, the dose taken by 90 per cent of arthritis sufferers, is the safest way to go—even though this most popular dose has not been conclusively studied.

Dr. Nissen has stated that the results released this week, which show that 400 milligrams of Celebrex per day cuts the risk factor for adverse cardiovascular events to 10 percent, is encouraging—and concludes that the 400 milligram dose, taken by a minority of patients, is the safest tested dose, so far. One can assume, then, that lower doses would be safer still.

However, that information will not be available until 2011 at the earliest.

In the meantime, Celebrex remains on the market, and is the only COX-2 selective inhibitor in the nonsteroidal anti-inflammatory drug (NSAID) class left on the market. In 2004 Merck took Vioxx, another COX-2, off the market after it was shown to raise the risk of heart attack and stroke. Early in 2005 Pfizer pulled Bextra off the market for similar reasons, complicated by the finding of a rare, but serious skin condition.

Celebrex was also under the microscope for cardiovascular concerns, but data from different studies didn't match up, and at the end of the day drug regulators decided that Celebrex should remain on the market, albeit with a black box warning highlighting the increased risk for heart attack and stroke.

That risk will remain for at least another three years, and Celebrex will be allowed to remain on the market while carrying that risk, until the PRECISION study is complete.

In the meantime, Pfizer has won patent protection from generic competitors for Celebrex until 2014, and appears to be making the most of that protection, and the fact that drug regulators have allowed Celebrex to remain on the market. Last spring Pfizer unveiled a 2.5-minute television commercial—the longest on record, next to an infomercial—promoting Celebrex. At the time, the manufacturer said it needed the time to fully explain the risk factors, and to dispel confusion amongst patients mistakenly thinking Celebrex was pulled off the market at the same time as Vioxx.

While sales took a hit after the Vioxx scare, Celebrex is coming back. Global sales were reported to be $1.7 billion last year, and analysts have projected Celebrex sales of $2.8 billion for 2008. Some projections show the drug pulling in $3.1 billion by 2012. Assuming results of the PRECISION study have been released by then and prove favorable, Pfizer will still have another two years to rake in the revenue, from an ever-increasing wave of ageing baby boomers suffering from arthritis, until generics come along two years later.

With that kind of performance, Pfizer should have a good war chest with which to deal with lawsuits stemming from people injured, or those who have died, allegedly from Celebrex.