United States of America. The Food and Drug Administration has approved rofecoxib (Vioxx), a new drug for treatment of osteoarthritis, menstrual pain and for the management of acute pain in adults. Rofecoxib is a nonsteroidal anti-inflammatory drug (NSAID) and is the second of the class of cyclooxygenase-2 inhibitors to be approved (the first was celecoxib approved in December 1998). Drugs of this class are believed to have a lower incidence of some adverse effects (particularly certain gastrointestinal effects such as ulcers and bleeding), while still providing effective treatment for conditions such as pain and osteoarthritis.

In trials comparing rofecoxib with ibuprofen, treatment with 25 mg to 50 mg of rofecoxib was associated with a significantly lower percentage of patients with endoscopic gastroduodenal ulcers than treatment with ibuprofen 2400 mg daily.

However, NSAIDs can cause a range of gastrointestinal problems. A few cases of serious gastrointestinal bleeding and one case of obstruction occurred among patients taking rofecoxib in clinical studies. Until further studies are performed, the drug labelling for rofecoxib will include a warning for doctors and patients about the risks associated with all NSAIDs including gastrointestinal ulceration, bleeding and perforation. Patients are advised to report promptly signs and symptoms of gastrointestinal ulceration or bleeding, skin rash, unexplained weight gain or swelling to their physician.

Rofecoxib does not affect platelet aggregation, although many other NSAIDs can interfere with this platelet function. However, like other NSAIDs, rofecoxib appears to have some potential for causing adverse effects on the kidney, particularly at higher doses.

Reference: FDA Talk Paper T99-24 dated 21 May 1999.