The potential for cardiac side-effects with the arthritis drug Rofecoxib, which was withdrawn from use last week, has been known for some time, it was claimed yesterday.
A number of doctors have contacted The Irish Times to express their concern that the drug, which is marketed here as Vioxx, was not withdrawn earlier. They said they have been concerned about its safety and that of other Cox II inhibitors for some time.
Vioxx was withdrawn from use last Thursday after research had shown that taking the drug long- term could increase the risk of heart attack or stroke between three and fourfold compared to patients taking a dummy pill. The drug is one of the latest generation of non-steroidal anti-inflammatory drugs (NSAIDS).
Cox II inhibitors, which block the action of the enzyme Cyclooxygenase and thereby inhibit joint inflammation, are licensed for use in people with osteoarthritis and rheumatoid arthritis. Other drugs in the Cox II class remain on the market. A Dublin doctor involved in medical education said: "The information we get from drug companies is different to that which comes from evidence- based sources of information. The drug industry is withholding research information in dubious ways to minimise serious side effects and is then using the law to quieten criticism."
This is a reference to a decision by Merck Sharp and Dohme, the manufacturers of Vioxx, to take legal action against an independent drug bulletin in Spain. Merck subsequently lost the case.
Dr Neil Boyle, medical director of Merck Sharp and Dohme in the Republic, was asked to comment on an article in the British Medical Journal which said the potential harm of Cox II inhibitors had been minimised in reports of research sponsored by drug companies. He said: "There was no suggestion of an increased cardiovascular risk with Rofecoxib at the pre-licensing stage."
"The VIGOR [Vioxx Gastrointestinal Outcomes Research\] study was the first time we picked up an issue, which we immediately provided to the European Agency for the Evaluation of Medicinal Products. We also recognised the need for long-term randomised trials, one of which was the APPROVE study, which led to the withdrawal of Vioxx last week. This is an indication of ethical and timely approach which Merck Sharp and Dohme adopted in response to this data."
A spokeswoman for the Irish Medicines Board said the Committee for the Proprietary Medical Products of the European Medicines Agency has reviewed the safety of all Cox II inhibitors and issued revised prescribing guidelines in November 2003. She said these were endorsed by the European Commission in April 2004. "All data that was available at the time was analysed during the review."
The spokeswoman confirmed the issue would be raised today at a meeting of the World Health Organisation's international drug monitoring programmes in Dublin and also at a European regulatory meeting in the Netherlands.