‘Vioxx like’ drugs may still be best option for arthritis

London: Scientists believe that despite the current concerns around anti-inflammatory drugs like Vioxx, they may still be the best option for treating some forms of arthritis.

In a Nature Reviews of Drug Discovery article this month the researchers from Imperial College London and Queen Mary, University of London examine the use of selective inhibitors of cyclo-oxygenase-2 (COX-2).

They argue that although this class of drugs, which includes Vioxx, has been associated with an increase in the risk of cardiovascular events such as heart attacks and strokes in some patients, the same may be true for traditional non-steroid anti-inflammatory drugs (NSAIDs).

All NSAIDs, including COX-2 inhibitors, work by blocking the actions of both COX-1 and COX-2 enzymes. Blocking COX-2 relieves inflammation and pain, but blocking COX-1 can increase the risk of gastric ulcers and bleeds. For this reason COX-2 selective drugs were developed with the simple aim that they would retain the therapeutic actions of NSAIDs (linked to inhibition of COX-2) but lose the gastric side effects (linked to inhibition of COX-1).

The researchers reviewed over one hundred papers on the subject and looked at the latest recommendations from organisations such as the American Federal Drugs Administration on the use of COX-2 inhibitors and NSAIDs.

The researchers point out that the calls for the removal of COX-2 inhibitors, and a return to using NSAIDs, may cause additional problems.
Although NSAIDs have been marketed for a number of years, they have never been required to meet the clinical trial standards now set for
COX-2 inhibitors, meaning they may not be any safer.

Professor Jane Mitchell, from Imperial College London, and one of the reviews authors, said: “Although some COX-2 drugs have been reported to increase the risk of heart attack and stroke, they may still remain the best option for treating arthritis in some patients without cardiovascular risk factors who cannot tolerate traditional NSAIDs because of gastric side effects.”

Professor Mitchell added: “This review shows us that despite the large scale use of NSAIDs and COX-2 inhibitors for a number of years, we still need more information on their benefits and potential risks and that more research needs to be done in this area. Looking at existing evidence, however, it would seem COX-2 inhibitors may be the best option for some patients. They are as effective as traditional NSAIDs, but with less gastric side effects than some older drugs.”

New arthritis drug fears

London: There are health concerns over a new arthritis drug which comes from the same drug family as Vioxx, which is at the heart of a US class action against the manufacturers.

The new drug Prexige, is a Cox-2 inhibitor, an anti-inflammatory, the best-known of which is Vioxx. A law suit against Vioxx manufacturer Merck Sharpe & Dohme, is currently ongoing in which 7,000 Americans claim they suffered heart attacks or strokes after taking it. The drug was removed from the market in 2004.

Prexige’s maker, Novartis, has carried out its biggest-ever trial involving 34,000 patients to prove that the drug is no more likely to cause heart attacks or strokes than standard painkillers such as ibuprofen or naproxen.

Prexige has now been licensed for use in the Britain by the Medicines and Healthcare products Regulatory Agency, the government agency responsible for making sure drugs are safe.

But following the scandal over Vioxx, many GPs are expected to be reluctant to prescribe it.

When Cox-2s became available in the late 1990s, they were seen to reduce the rate of stomach ulcers caused by existing painkillers such as aspirin. Thousands of patients end up in hospital each year because of ulcers linked to painkilling drugs and it is estimated up to 2,500 Britons a year die as a result.

Patients with heart disease or at high risk of a stroke have been advised not to take Cox-2s since Vioxx was taken off the market.

Trials on Prexige show it reduces pain as successfully as some other Cox-2s and nonsteroidal anti-inflammatory drugs. But it reduces the rate of stomach problems, including ulcers, by up to 79 per cent compared with two other commonly-used drugs.

There was no difference in the cardiovascular risk in patients taking the new drug compared with the painkillers ibuprofen or naproxen.