COX-2 Inhibitors Prescribed to Many Patients Who Could Benefit From Older, Less-Expensive Medications, Study Finds
Almost two-thirds of individuals who took COX-2 inhibitors in 2002 had a low risk for gastrointestinal problems -- the "main selling point" for the use of such medications -- according to a study published on Monday in the Archives of Internal Medicine, USA Today reports (Rubin, USA Today, 1/24).
For the study, researchers from Stanford University and the University of Chicago examined data from two studies conducted by the National Center for Health Statistics and found that between 1999 and 2002, only 2% of participants were at "high risk" for gastrointestinal side effects and should have taken COX-2 inhibitors rather than older nonsteroidal anti-inflammatory drugs (Dai et al., Archives of Internal Medicine, 1/24).
NSAIDs, such as ibuprofen and naproxen, are linked with gastrointestinal side effects, which prompted some physicians to favor COX-2 inhibitors after they entered the market in 1999. COX-2 inhibitors cost 10 to 15 times more than NSAIDs (Ritter, Chicago Sun-Times, 1/24). However, recent concerns about the safety of COX-2 inhibitors prompted Merck in September 2004 to voluntarily withdraw Vioxx from the market and Pfizer last month to end all direct-to-consumer advertisements for Celebrex (California Healthline, 1/18).
According to the new study, the percentage of participants at low risk for gastrointestinal side effects who received COX-2 inhibitors increased from 40% in 1999 to 66% in 2002 (Archives of Internal Medicine, 1/24). The study said that such individuals "could have obtained just as much pain relief" from NSAIDs, the Chicago Sun-Times reports (Chicago Sun-Times, 1/24).
In addition, the study found that physicians prescribed COX-2 inhibitors to participants with congestive heart failure or liver or kidney dysfunction -- "conditions that should have prompted restricted use of the drugs," the Los Angeles Times reports (Maugh, Los Angeles Times, 1/22).
Population studies have indicated that COX-2 inhibitors "generally are no better at relieving arthritis and other painful conditions than older anti-inflammatory drugs," the Sun-Times reports (Chicago Sun-Times, 1/24).
Randall Stafford, a Stanford University internist and an author of the study, said that marketing efforts by Merck, which in 2000 spent $161 million to promote Vioxx, contributed to the increased number of COX-2 inhibitor prescriptions. Stafford said, "There's an assumption that newly approved drugs somehow have proven themselves to be better than what's already available" (USA Today, 1/24).
G. Caleb Alexander, a University of Chicago professor and an author of the study, said, "What we saw was widespread, rapid adoption of an interesting and promising but expensive and largely untested medication by millions of people with little or nothing to gain from long-term use" (Los Angeles Times, 1/22).