FDA Likely to Put Warning on Arthritis Drug Bextra®
WASHINGTON, DC -- November 12, 2004 -- The Food and Drug Administration (FDA) may add a "black box" alert to the insert for the arthritis drug, Bextra®, warning that the medicine can cause a severe allergic skin reaction known as Stevens-Johnson syndrome in some users. Considered a disorder of the immune system, Stevens-Johnson syndrome leads to a painful blistering of the skin and mucous membranes. The patient's skin may slough off; eyesight may also be affected. In about 3%-15% of cases, Stevens-Johnson syndrome can prove fatal (Stevens-Johnson Syndrome, Steven Parillo, eMedicine).
Since 2002, Bextra®'s manufacturer, Pfizer, has included a statement about Stevens-Johnson syndrome within its prescribing information. It recommends that a patient who develops a skin rash while taking Bextra® discontinue use of the drug. Pfizer has announced that it may be required to add the black box alert, which is the most serious FDA warning about a drug's effects.
Symptoms of Stevens-Johnson syndrome usually develop within two to three weeks after a susceptible patient takes a drug such as Bextra®. After they discontinue taking the drug, patients receive treatment that is similar to that given for thermal burn victims. Hospitalization and supportive care may be required. Some experts believe that steroids can be helpful.
Bextra® May Cause Heart Problems
The risk of Stevens-Johnson syndrome is not the only problem plaguing Bextra® users. Bextra® may also increase the risk of heart problems. This week Dr. Garret FitzGerald, a heart doctor and pharmacist, reported preliminary results of studies involving 5,930 patients taking part in 12 clinical trials involving Bextra®. The number of heart attacks or strokes among patients using Bextra® was 2.19 times the number who took placebos (NY Times, November 10, 2004, reporting on American Heart Association meeting). These were mainly patients who had undergone cardiac bypass surgery. Pfizer had previously reported that Bextra® may increase heart attack risk (see Bextra® May Cause Heart Problems).
How is Bextra® Used?
Also known as valdecoxib, Bextra® is used to relieve the symptoms of osteoarthritis and rheumatoid arthritis, and to treat painful menstrual periods (dysmenorrhea). The FDA rejected Pfizer's application to have Bextra® approved to treat migraine headaches. A related arthritis drug, Vioxx® (rofecoxib), was withdrawn from the market last month because it increased the risk of heart attacks and strokes.
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.