Availability of COX-2 Inhibitors After the Vioxx Withdrawal
When Vioxx was withdrawn from the worldwide market in 2004, patients had no choice but to stop taking the medication. The only other COX-2 inhibitors on the market were Celebrex and Bextra, both manufactured by Pfizer. Patients who did not wish to continue taking COX-2 inhibitors were given the option of trying a non-selective NSAID.Below, you will find information about the medication alternatives of former Vioxx patients, including other COX-2 inhibitors and non-selective NSAIDs.
Celebrex (generic name celecoxib), manufactured by Pfizer, was the first COX-2 inhibitor approved by the FDA. Celebrex was released in 1999, mere months ahead of Merck’s competing drug, Vioxx. The two drug giants used their strongest marketing efforts to snatch up the new customer base of arthritis sufferers, who numbered in the millions and had been offered no notably effective medications up to that point. Celebrex is also approved by the FDA for the treatment of Ankylosing Spondylitis (spinal arthritis), dysmenorrhea (severe menstrual pain), Familial Adenomatous Polyposis (precancerous colorectal polyps), and acute pain.
Bextra (generic name valdecoxib), also manufactured by Pfizer, was withdrawn from the US market in 2005. Shortly after the withdrawal of Vioxx, the safety of the entire class of COX-2 inhibitors was called into question. The FDA determined that the benefits of Celebrex outweighed its risks, and it was allowed to remain on the market. In the case of Bextra, however, the elevated cardiovascular risks, and a rare incidence of a potentially fatal skin reaction, caused the FDA to recommend its withdrawal.
Arcoxia (generic name etoricoxib) was intended to be the new COX-2 inhibitor by Merck, but in April of 2007, Merck’s request for FDA approval of Arcoxia was denied. The FDA has requested further safety and efficacy data in support of Arcoxia be provided before it will approve the drug. Arcoxia is currently approved in more than 40 countries, but not in the US.
Prexige (generic name lumiracoxib), manufactured by Novartis, was first approved for use in the European Union in November of 2006, and it was quickly approved in several other countries around the globe. By August of 2007, Prexige was withdrawn in Australia. In September of 2007, the FDA denied approval of Prexige in the US pending further safety data. In October of 2007, Prexige was withdrawn in Canada, and in November, it was withdrawn from several countries in the European Union.
Although Prexige is a selective COX-2 inhibitor, it works slightly differently from other COX-2 inhibitors like Celebrex or Vioxx. The chemical makeup of Prexige causes it to bond to a different area on the COX-2 enzyme. The basic effect of suppressing the COX-2 enzyme is the same, but Prexige was withdrawn because of a high incidence of severe liver damage, rather than cardiovascular complications as in the cases of Vioxx and Celebrex.
Licofelone (also called ML3000) is a new kind of NSAID called a COX/LOX inhibitor. While COX inhibitors react with the enzyme cyclooxygenase, LOX inhibitors react with the enzyme lipoxygenase. Both enzymes are involved in the production of prostaglandins, which are the pain- and inflammation-causing agents targeted by this entire drug class. Licofelone was developed by a German pharmaceutical company called Merckle GmbH for the treatment of osteoarthritis. Licofelone is still in testing stages and has not yet been submitted for approval. It is designed to have even fewer gastrointestinal (GI) side effects than other selective COX-2 inhibitors. In clinical trials, Licofelone has shown fewer GI complications compared to naproxen in osteoarthritis patients.
Non-selective NSAIDs are another option for former Vioxx patients. NSAIDs have been around much longer than COX-2 inhibitors, and have never been shown to cause the same severity of complications. Unlike selective COX-2 inhibitors, like Vioxx, non-selective NSAIDs inhibit both the COX-1 and COX-2 enzymes. The COX-2 enzyme is responsible for pain and inflammation, while the COX-1 enzyme helps to protect our stomach and intestinal lining from corrosion. By inhibiting both enzymes almost equally, NSAIDs offer pain relief accompanied by a higher risk of gastrointestinal side effects, including ulcers. Ulcerations of the stomach and intestines can lead to internal bleeding, and in extreme cases, death. The risk of these serious side effects is relatively small, but many people experience some gastrointestinal complications with prolonged or high-dosage NSAID use.
Several NSAIDs are available over-the-counter, including aspirin and ibuprofen, which are sold under various brand names. Prescription NSAIDs currently approved in the US include:
These medications may be prescribed for various pain or inflammation-related conditions, as determined by your doctor. Because individuals react differently to drugs, it is not unusual for your doctor to try different NSAIDs until you find the one most effective for your condition and body chemistry.