Although cyclooxygenase 2 (COX-2) inhibitors, also called “coxibs,” can be easier on the gastrointestinal system than nonsteroidal anti-inflammatory drugs (NSAIDs are, some physicians prefer to err on the side of caution by prescribing a gastroprotective agent (GPA) as well. The coxibs were named after two recently developed anti-inflammatory drugs, canadian celecoxib (Celebrex drug, Pharmacia) and rofecoxib (Vioxx®, Merck).
Canadian researchers analyzed data from 42,267 patients who were taking COX-2 inhibitors; 8,235 patients who were taking NSAIDs, and 19,716 patients who received acetaminophen. The researchers concluded that adding a GPA to a coxib constitutes an unnecessary financial burden, particularly if the GPA prescription is unwarranted.
Physicians in the study were more likely to prescribe coxibs than NSAIDs for patients who were older or sicker or who had risk factors associated with gastropathy from NSAID use. They also tended to prescribe coxibs over acetaminophen for patients with musculo-skeletal disorders and osteoarthritis, presumably because of the anti-inflammatory analgesia associated with coxibs. (At the time of the study, rofecoxib had not yet been indicated for rheumatoid arthritis.)
As coxibs gained popularity, it was expected that prescriptions for GPAs might decline along with the decrease in NSAID prescriptions, but that was not the case. GPAs in this study, however, were prescribed 47% less often for coxib users than for NSAIDs users. Studies have indicated that coxibs—although more expensive than NSAIDs—would be cost-effective in patients at high risk for gastrointestinal events with NSAIDs, the investigators noted.
Other studies have shown that the cost-effectiveness of rofecoxib, compared with that of the nonselective NSAIDs, for patients with osteoarthritis is “sensitive to the rate of prophylactic GPA use,” according to the authors.
When the researchers re-analyzed the data, keeping only the patients who did not have any previous gastrointestinal events, cancer, or any filled prescriptions for coxibs, NSAIDs, or acetaminophen, a GPA co-prescription was 61% less frequent with coxibs than with NSAIDs. A co-prescription of a GPA with coxibs was equivalent to one with acetaminophen— a striking finding, the researchers say, considering that physicians do not perceive acetaminophen as being toxic to the gastrointestinal tract.