COX-2 drugs under scrutiny
Adapted from Jan./Feb. 2005 Psoriasis Advance
The COX-2 inhibitor Vioxx (also known by its generic name, rofecoxib) was "x"-ed out of the arthritis drug arsenal after reports it increased the risk of heart attacks and stroke. COX-2s are a class of NSAIDs (nonsteroidal anti-inflammatory drugs) often prescribed for arthritis patients, including those with psoriatic arthritis, to decrease inflammation and pain.
In a trial for colon polyp prevention, Vioxx's manufacturer, Merck, discovered participants had double the risk of a heart attack compared to those taking a placebo. Merck pulled the drug from the market in September 2004 due to safety concerns.
COX-2 inhibitors are under increased scrutiny following the Vioxx removal, but not all have been found to have the same side effects. Celebrex (also known by its generic name, celecoxib), Bextra (also known by its generic name, valdecoxib) and two new COX-2s not yet on the market need further study to determine if the risks are specific to Vioxx or if they have broader applicability.
On Dec. 23, 2004, the Food and Drug Administration (FDA) issued a Public Health Advisory recommending limited use of COX-2 inhibitors. The advisory contains the following guidelines:
- Patients who are at a high risk of gastrointestinal bleeding, have a history of intolerance to nonselective NSAIDs, or are not doing well on nonselective NSAIDs may be appropriate candidates for COX-2 selective agents.
- Individual patient risk for cardiovascular events and other risks commonly associated with NSAIDs should be taken into account for each prescribing situation.
- Consumers are advised that all over-the-counter (OTC) pain medications, including NSAIDs, should be used in strict accordance with the label directions. If use of an NSAID is needed for longer than 10 days, a doctor should be consulted.
People who are using a COX-2 inhibitor should talk to their doctor to consider the emerging information regarding the risk of heart attack and stroke among COX-2 users.
Update:
On April 7, 2005, Bextra was voluntarily removed from the market by its manufacturer, Pfizer, at the request of the FDA. In requesting the action, the FDA said that the drug's potential risks were greater than its benefits and also cited reports of serious and potentially life-threatening skin reactions in patients using Bextra.
The FDA also announced new label requirements for both prescription and over-the-counter NSAIDs. Prescription labels for prescription drugs such as Celebrex will now carry a "black box warning" (the FDA's strongest warning) stressing the "potential for increased risk of cardiovascular events and the well described, serious, potential life-threatening gastrointestinal bleeding associated with their use."
The labels of non-prescription (over-the-counter) NSAIDs, such as Advil (also known by its generic name, ibuprofen) and Aleve (also known by its generic name, naproxen), will include more specific information about their potential cardiovascular and gastrointestinal risks. The changes do not apply to aspirin.
Additionally, the FDA announced that it will "carefully review any proposal from Merck for resumption of marketing of Vioxx."
The FDA's actions diverge from the recommendations of an FDA expert advisory panel, which, on Feb. 18, 2005, voted in favor of allowing COX-2 inhibitors Celebrex and Bextra to remain available. The panel also narrowly voted (17-15) in favor of allowing Vioxx back on the market under strict conditions.
More information from the FDA:
 Press release: FDA announces changes to class of marketed NSAIDs
Public health advisory: FDA announces important changes and additional warnings for COX-2 selective and non-selective NSAIDs
COX-2 information page
COX-2 questions & answers
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