Vioxx was used to reduce pain and inflammation caused by osteoarthritis, as well as acute pain in adults and menstrual pain. It was one of a new kind of nonsteroidal anti-inflammatory drug (NSAID) approved by FDA.

Subsequently, the FDA approved Vioxx to treat the signs and symptoms of rheumatoid arthritis in adults and children. Vioxx is the only NSAID to have demonstrated a lower risk of undesirable side effects such as gastrointestinal ulcers and bleeding.

Unfortunately, three-year data from a prospective, randomized, placebo-controlled clinical trial showed increased relative risk for confirmed cardiovascular events, such as heart attack and stroke, beginning after 18 months of continuous treatment in the patients taking Vioxx compared to those taking placebo. Merck's decision was to voluntarily recall Vioxx and to reimburse anyone with unused medication.

Merck expects about 16,000 people to file legitimate Vioxx law suits against the company. Wall Street analysts project that the number of successful law suits will be significantly higher.