What is the COX enzyme?
The cyclooxygenase (COX) enzyme has two forms: COX-1 and COX-2. COX-1 is found in a lot of cells all the time, notably the lining of the stomach where it regulates acid production. COX-2 is not present in most cells normally, only appearing when things are going wrong. As a result, COX-2 was thought to be responsible for the bad effects of the COX enzyme—pain and inflammation. Vioxx was developed based on this belief that COX-2 was responsible for the bad effects of the COX enzyme and to reduce or even eliminate the gastrointestinal risks involved with the non-selective (traditional) NSAIDs like Aspirin ( acetylsalicylic acid, ASA), Ibuprofen, Nabumetone and Naproxen, that inhibit both COX-1 and COX-2 enzymes. However, COX-2 serves other purposes besides its role in inflammation. Among the purposes the COX-2 enzyme serves is that it plays a major role in controlling the cardiovascular system - stopping platelets from forming blood clots (thrombi - plural form of thrombus) in the heart, and preventing damage to vessels. It also serves other functions that are beyond the scope of this FAQ to explain.
Other Vioxx FAQs
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Q:
What is Vioxx?
A: Vioxx (rofecoxib) is a prescription COX-2 inhibitor nonsteroidal anti-inflammatory drug (NSAID). Vioxx works by inhibiting the COX-2 form of the COX enzyme to block … More -
Q:
Why has Vioxx been withdrawn from the market?
A: New research shows that a major Vioxx side effect is a greatly increased risk of cardiovascular (CV) events such as heart attack or stroke if used long-term. More -
Q:
Were there any warning flags that led to Merck's recall of Vioxx?
A: Ever since the FDA sent a warning letter to Merck in 1999 calling Merck's promotional materials "false and misleading," and when the FDA directed Merck … More -
Q:
What evidence supports the withdrawal?
A: Merck's decision to withdraw Vioxx from the market is based on new data from a trial called the APPROVe (Adenomatous Polyp Prevention on VIOXX) trial. In the … More -
Q:
Did the Food and Drug Administration (FDA) require this action?
A: No. Merck made this decision independent of input from the FDA. The FDA agrees with the company that there appears to be significant safety concerns for patients, … More -
Q:
What action did the FDA take?
A: The FDA issued a public health advisory concerning the use of Vioxx. This advisory is based on Merck voluntarily withdrawing Vioxx from the market due to safety … More -
Q:
Why wasn't the APPROVe trial stopped earlier?
A: The APPROVe trial began enrollment in 2000 and was being monitored by an independent data safety monitoring board (DSMB). It was not stopped earlier because the … More -
Q:
What did the FDA know about the risk of heart attack and stroke when it approved Vioxx?
A: The FDA originally approved Vioxx in May 1999. The original safety data included approximately 5,000 patients taking Vioxx and did not show an increased risk of heart … More -
Q:
What are NSAIDs?
A: NSAIDs are a large group of drugs that have pain-relieving (analgesic) and fever reducing (antipyretic) effects, as well as the effect of reducing inflammation when … More -
Q:
Does the withdrawal of Vioxx from the market suggest that other drugs in the same class are dangerous?
A: The results of clinical studies with one drug in a given class do not necessarily apply to other drugs in the same class. Chronic use of NSAIDs has risks which … More
