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Wednesday, March 05, 2003Of the 2 million rheumatoid arthritis sufferers, thousands try one of the four drugs each year. Tuesday, the FDA's scientific advisers began two days of debate over how big a risk each medication poses and whether stronger warnings or restrictions are needed. The consumer advocacy group Public Citizen is pushing for one of the medicines, Arava, to be banned. Reaction within the FDA is mixed. An agency analysis posted on the FDA's Web site Tuesday recommends a ban--citing 54 U.S. cases of liver failure or damage and eight deaths linked to the drug. Higher-ranking FDA officials will tell agency advisers today that they disagree, citing additional analyses that argue there's no proof Arava is more dangerous than competing treatments. ''There are cases of liver injury that are possibly or probably related to use of Arava, but we also think it continues to have a place,'' said FDA drug chief Dr. John Jenkins. Arava works by blocking an enzyme that's involved in autoimmune inflammation. The enzyme is also involved in the synthesis of pyrimidine, one of the buildling blocks of DNA. It's difficult to say if the liver inflammation is caused by the drug, and if it is, if it's a risk that's worth taking. A lot of drugs cause liver inflammation, including the other commonly prescribed analgesics for arthritis pain. Arava isn't the only one to be put under the microscope lately: The FDA also is struggling to determine if three other medicines--Enbrel, Remicade and Humira--are linked to 170 cases of lymphoma, a hard-to-treat immune system cancer, reported since 1998. Again, it's diffiicult to say whether the association is real, but all of three of these drugs act by inhibiting tumor necrosis factor, a molecule that's used by the body to fight tumor cells. It also seems to be involved in the inflammation process of rheumatoid arthritis. It wouldn't be too surprising if drugs that block tumor necrosis factor also happen to associated with higher incidences of lymphoma. Rheumatoid arthritis can be very painful, and very destructive. Compare this picture of a normal (but fractured) wrist, with this picture of a rheumatoid wrist to see just how much damage it does to joints and bones. What all of these newer drugs have in common is that they slow down this joint destruction rather than just treat the pain. The older drugs used for this, such as methotrexate, also have potential for serious side effects, so the matter isn't as clearcut as it might seem at first. It becomes a matter of how much risk we're willing to tolerate to treat a devastating disease, and whether or not these newer drugs are any safer and any more effective than the older drugs. posted by Sydney on 3/05/2003 09:00:00 AM 0 comments 0 Comments: |
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