he promise of selective COX-2 (cyclooxygenase type 2) inhibitors is that they will be as effective as traditional nonsteroidal anti-inflammatory drugs (NSAIDs) at relieving inflammation and pain but will cause only a fraction of the adverse GI effects. The first selective COX-2 inhibitor will likely be marketed in early 1999, and health plan administrators will have to decide how to cover the new drugs. The new agents appear to have a better safety profile than traditional NSAIDs, at least as far as GI effects are concerned—and they are expected to be priced substantially higher than current NSAIDs.

An article in the May 11, 1998, issue of BusinessWeek estimated the US market for celecoxib (Celebrex) and rofecoxib (Vioxx)—selective COX-2 inhibitors from Searle and Merck—at $3.2 billion and $2.4 billion, respectively. Another estimate of the potential economic impact of these drugs was provided by Tanouye in the Wall Street Journal. She reported that, although only 2–4% of arthritis patients taking NSAIDs have severe adverse GI events, half of the arthritis patients in Michigan’s Blue Cross Blue Shield plan are expected to switch to selective COX-2 inhibitors after the drugs become available. If the new drugs are priced between $2 and $5 a dose, as expected, Tanouye reported, the cost of obtaining a selective COX-2 inhibitor may be up to 17 times the cost of a generic NSAID. And arthritis patients may not be the only ones to receive these new agents. Any gains in safety will certainly appeal to other patients who take NSAIDs. NSAIDs are associated with an estimated 10,000–20,000 deaths and 100,000