Canada, USA. Health Canada is advising consumers of safety information related to the selective cyclo-oxygenase (COX-2) inhibitor rofecoxib (Vioxx), a non-steroidal anti-inflammatory drug (NSAID) approved for the treatment of osteoarthritis, menstrual pain and acute pain in adults. Results from a post-market clinical trial (VIGOR: Vioxx Gastrointestinal Outcomes Research) show that a risk of gastrointestinal toxicity associated with the use of rofecoxib exists although to a lesser extent than another NSAID, naproxen. Results also show a higher rate of cardiovascular adverse events in the rofecoxib group. Patients experiencing symptoms of gastrointestinal toxicity such as gastric pain and blood in stools and those who develop fluid retention or swelling, shortness of breath, weakness, fatigue, excessive weight gain or chest pain while on rofecoxib therapy should inform their physician immediately. In addition, patients with a medical history of hypertension, ischaemic heart disease, fluid retention or heart failure are advised to discuss their medical condition with their physician before taking rofecoxib.

A ‘Dear Healthcare Professional’ letter issued by Merck regarding changes to the labelling for rofecoxib (Vioxx) has been posted on the US FDA website. The letter advises of updates made to the Warnings, Precautions and Clinical Studies sections of the labelling, and includes new cardiovascular and gastrointestinal safety information, also derived from analyses of the VIGOR study, that rofecoxib was associated with a significantly higher rate of serious cardiovascular throm-botic events and, a significantly lower incidence of serious upper gastrointestinal adverse events, compared with naproxen. The labelling also includes the recommended daily dose of rofecoxib for the treatment of rheumatoid arthritis, a recently approved indication.

References 3 and 4 below provide more information on the VIGOR study.

Reference:

1. Health Warnings/Advisories from Health Canada, 19 Apr 2002. Available from URL: http://www.hc-sc.gc.ca

2. ‘Dear Healthcare Professional’ letter from Merck, Apr 2002. Available from URL: http://www.fda.gov

3. Comparison of upper gastrointestinal toxicity of rofecoxib and naproxen in patients with rheumatoid arthritis. VIGOR study group. N Engl J Med 343(21): 1520-8, 23 Nov 2000. 4. http://www.fda.gov/ohrms/ dockets