New pain relievers may lower gastrointestinal problems but at increased cost

October 1, 2004

Everyone's familiar with nonsteroidal anti-inflammatory medications (NSAIDs). These are household names, sold in every drugstore, and consumers use them for headaches, athletic injuries, and other minor aches and pains.

Selective COX-2 Inhibitors NSAIDs target the cyclooxygenase (COX) enzymes, which synthesize prostaglandins.

COX-1 stimulates stomach mucus (which protects the lining of the stomach) while COX-2 is part of the immune response, and produces inflammation. Recently pharmaceutical manufacturers have developed a new class of medications, called selective COX-2 inhibitors, which only work against COX-2. They include:

These selective COX-2 inhibitors are just as effective against pain and inflammation as earlier NSAIDs, but they're much less likely to cause short-term GI problems. "They clearly are easier on the stomach. Whether they also prevent the rare but more serious gastrointestinal side-effects is not clear at this point," says Dr. Abramowicz. "In addition, some studies suggest that Vioxx may lead to a higher rate of heart attacks."

COX-2 inhibitors cost far more than generic NSAIDs, and they've been heavily promoted to physicians (free samples) as well as consumers (catchy jingles on TV). COX-2 usage has grown dramatically over the past few years, and annual U.S. spending on COX-2s now exceeds $6 billion, according to the Wall Street Journal.

Meanwhile, many MCOs have responded by instituting higher copayments for COX-2s compared with generic NSAIDs. One recent study looked at almost 21,000 people with either osteoarthritis or rheumatoid arthritis, enrolled in health plans with tiered formularies. On average, patients in a two-tier plan paid nearly twice as much for COX-2s compared with NSAIDs ($9.67 vs. $5.44) while patients in three-tier plans paid nearly three times as much ($15.35 vs. $5.46.)

These formularies affected member usage patterns, encouraging the use of generic NSAIDs and discouraging COX-2 selective inhibitors.

This study found that even people with serious gastrointestinal comorbidities were significantly less likely to use COX-2s if they were enrolled in a three-tiered plan.