Bextra®, An Arthritis Drug Related to Vioxx®, May Also Cause Heart Problems
NEW YORK, NEW YORK -- October 22, 2004 -- Bextra® (valdecoxib) may cause heart problems in patients who have undergone heart bypass surgery, according to the drug's manufacturer, Pfizer (Press Release, October 15, 2004). The drug is used to relieve the symptoms of osteoarthritis and rheumatoid arthritis, and to treat painful menstrual periods (dysmenorrhea). Another related drug, Vioxx® (rofecoxib, manufactured by Merck), was withdrawn from the market last month because it increased the risk of heart attacks and strokes.
Pfizer reported on two studies in which Bextra® was used alone or in combination with parecoxib, an injectable sulfonamide-based drug very similar to Bextra®. One study published last year involved 462 patients at hospitals in the United States, Canada, Germany, and the United Kingdom undergoing heart bypass surgery (J Thorac Cardiovasc Surg. 2003 Jun;125(6): 1481-92). Compared to patients taking a placebo, those taking Bextra®/parecoxib had a greater chance of having serious reactions, including wound infections and heart attacks. A later study has not yet been published, Pfizer said, but it also links further heart problems to Bextra® use in heart surgery patients.
Bextra®, Celebrex® and Vioxx® are COX-2 Inhibitors
Both Bextra® and Vioxx® are nonsteroidal anti-inflammatory drugs (NSAIDs) that block cyclooxygenase, an enzyme needed for the production of prostaglandins. Prostaglandins may cause inflammation and pain. Bextra® and Vioxx® interfere with the form of cyclooxygenase known as COX-2, and are therefore referred to as COX-2 inhibitors.
Pfizer manufactures another popular COX-2 inhibitor, Celebrex® (celecoxib). In one study, Celebrex® users with osteoarthritis and rheumatoid arthritis did not have a greater risk of heart attacks compared with those taking more traditional NSAIDs such as ibuprofen (Celecoxib Long Term Arthritis Safety Study or CLASS at JAMA. 2000 Sep 13;284(10): 1247-55). However, the study only took place over a period of six months. Also, Celebrex® users may have had an increased risk of blocked blood flow in the artery to the heart ("cardiac ischemia") during this time period (FDA, Celecoxib, Medical Officers Review, June 14, 2000; Press Release, Public Citizen, September 30, 2004)
Pfizer has announced plans to test Celebrex® further to see whether its use leads to heart problems, or whether it can improve heart function (Pfizer Press Release, October 18, 2004). The company expects to enroll over 4,000 patients who have had recent heart attacks and who also have osteoarthritis. It will compare patients using Celebrex® to those who are taking no pain medications.
The new Celebrex® study has been greeted with some skepticism. "I would not put any of my patients who are at high cardiovascular risk on any drug that is a member of this class [COX-2 inhibitors] based on the current evidence," said Dr. Garret FitzGerald, a heart doctor at the University of Pennsylvania (New York Times, October 19, 2004). The federal Food and Drug Administration (FDA) has also said that any clinical trial of COX-2 inhibitors using high risk heart patients "needs careful scrutiny."