Additional evidence of problems with Vioxx type drugs

As many of our readers know, Vioxx is a drug that belongs to a category of drugs called the Cox-2 inhibitors since these drugs target an enzyme in the stomach called Cox-2. Vioxx was recalled because it increased the risk of heart attacks (tens of thousands of Vioxx patients died from these heart attacks and others have suffered irreparable damage to their cardiovascular systems).

There are two other drugs on the market right now that belong to the Cox-2 category: Celebrex and Bextra (they are sometimes sold by other brand names outside the United States). When it was found that Bextra was causing many cardiovascular complications, FDA directed its maker, Pfizer, to add a warning to Bextra label. More research has shown that Celebrex also has adverse side effects but the data is not conclusive yet. Pfizer is insisting that while both Celebrex and Bextra are Cox-2 drugs their molecular structure is different from that of Vioxx, and hence, they are not as dangerous as Vioxx. This is their main line of argument against recalling Celebrex and Bextra though most medical experts think that in the interest of patient safety, both these drugs should be recalled. (Related article: FDA issues an advisory against Celebrex and Bextra)

The doctors, patients, and drug agencies all over the world are closely watching whether FDA will decide to recall Celebrex and/or Bextra in early 2005. There is a lot of concern about Cox-2 drugs and it is generally believed that they do not provide as many benefits as the risks that they present. (Related article: All Vioxx type Cox-2 drugs under review)

Now another startling revelation shows that Cox-2 drugs may not be all that safe after all. Deramaxx (known generically as deracoxib) is a COX-2 inhibitor approved for relieving arthritis and post-surgical pain in dogs (not approved for humans). It seems that several dogs have died after consuming this drug and its manufacturer, Novartis AG, failed to give the government prompt, accurate reports about the deaths. It is important to point out that Novartis sells a Cox-2 drug called Prexige (lumiracoxib) as an alternative to Vioxx and while the company has temporarily withdrawn the dossier for Prexige from the Mutual Recognition Procedure in Europe to await the outcome of the EMEA cardiovascular safety review of all COX-2 inhibitors, Prexige has been approved in 21 countries to date, including Australia, New Zealand and several countries in Latin America, including Argentina, Brazil and Mexico. (Related article: Novartis offers an alternative to Vioxx)

The FDA, in a warning letter dated Nov. 29, said Novartis Animal Health Services should have forwarded complaints about deaths and health problems in dogs given Deramaxx within 15 working days, but in some cases delayed as long as 10 months. Some reports, including ones involving deaths, appeared to have incorrect dates, the FDA said. The company also failed to submit proper information about post-approval studies of Deramaxx, the FDA charged. While this new information has no bearing on the ongoing review of Celebrex and Bextra, but it does show that Cox-2 drugs need to be evaluated more carefully and in the meantime, these drugs should be recalled.

Recommended article: Vioxx recall makes drug agencies worldwide more careful