New Zealand Study Indicates This Increased Risk Is "Class Effect" of COX-2 Inhibitors
Pfizer Inc.'s painkiller Celebrex doubles a patient's risk of having a heart attack, according to a report about a New Zealand study published in the Journal of the Royal Society of Medicine in the first part of 2006.
A March 1, 2006 Reuters article about the New Zealand study gave this summary:
[The researchers] looked at four trials involving 4,422 patients which compared Celebrex to a placebo. The study . . . showed [Celebrex] was associated with a 2.26 fold increased risk of a heart attack.
In six other studies, patients taking [Celebrex] had a 1.88 fold raised risk of a heart attack compared to patients taking older painkillers such as ibuprofen and paracetamol.
Richard Beasley, one of the lead researchers for the New Zealand study, said their analysis of these drug trials involving Celebrex (celecoxib) suggests this increased risk of having a heart attack is common to the entire class of drugs known as COX-2 inhibitors.
Merck & Co. Inc. withdrew Vioxx from the market in September 2004 after a study showed it doubled the risk of a stroke or heart attack in patients taking it for 18 months or more. Thereafter, in April 2005, Pfizer voluntarily recalled Bextra due to these cardiovascular side effects as well as an increased risk of developing serious skin reactions like Stevens-Johnson Syndrome (SJS). Due to these two drug recalls, Celebrex is the only the COX-2 inhibitor still available in the U.S.
In August 2005, however, Pfizer put a "black-box" warning on Celebrex label, or package insert, following a recommendation by the FDA, which warns that Celebrex may increase the risk of cardiovascular events, including heart attack and stroke.
In 2005, also, the European Medicines Agency (European Union's drug regulator) issued guidance about the use of COX-2 pain relievers, stating in relevant part that Celebrex should not be prescribed to people with ischemic heart disease or stroke, and when prescribed the lowest dose and shortest course of Celebrex should be used.
Returning to the March 1 article published by Reuters:
"Our evidence shows an increased risk of heart attack in patients taking [Celebrex]," said Beasley.
"Drug regulatory authorities need to urgently re-examine the assessment of [Celebrex] in light of these findings," he added in a statement.
"Given the popularity of [Celebrex] in the treatment of arthritis, drug regulators must undertake an up-to-date risk assessment based on the findings presented here," said Beasley.
A spokesman for Pfizer contested the analysis done by the New Zealand researchers in a March 1, 2006 article in The Wall Street Journal:
"The FDA, [the European Medicines Agency] and other health authorities around the world have concluded that the benefits of Celebrex continue to outweigh its risks, and, as a result, Celebrex is the only Cox-2 inhibitor remaining on the market today."
In December 2005 the Cleveland Clinic announced that it would lead an international study to learn whether painkillers taken for arthritis, including Celebrex, Ibuprofen and Naproxen, are safe for those at risk of heart problems. The results from that study -- known as the PRECISION study -- will not be available, however, until 2010 at the earliest.
(Posted by: Tom Lamb)