The dose used in the clinical trials was of 25 mg for rofecoxib, for a period of 30 days or 20 mg once/day for valdecoxib
for two weeks.
The newer COX-2s have improved biochemical selectivity and include etorocoxib, valdecoxib
, parecoxib and lumiracoxib (Figure 2).
Cardiovascular safety of the cyclooxygenase-2 selective inhibitors parecoxib and valdecoxib
in the postoperative setting: an analysis of integrated data.
Rofecoxib was voluntarily withdrawn from the market in September 2004 and valdecoxib
was withdrawn in April of 2005, and these events affected physician prescribing habits.
n Bextra (Valdecoxib
), prescribed to treat arthritis.
Finally, in April 7, 2005, the FDA requested Pfizer to voluntarily withdraw valdecoxib
from the market, and Pfizer did so.
Searle's 2005 recall of Bextra (valdecoxib
) has cost >$2 billion in legal awards and expenses.
Os seletivos para COX-2 sao representados pelo celecoxib, rofecoxib, valdecoxib
e nimesulida e, ainda, os parcialmente seletivos para COX-2 como o meloxicam e o etodolaco.
Cardiovascular toxicity of valdecoxib
. New England journal of Medicine 351, 2767.
Other well-known examples of withdrawals are the antidiabetic Avandia, (rosiglitazone) from GlaxoSmithkline, the anti-inflammatory drugs Vioxx (rofecoxib) from Merck, Bextra (valdecoxib
) from Pfizer, Iressa (gefitinib) from AstraZeneca and Xigris (drotrecogin alfa) from Eli Lilly.
However, the development of serious adverse reactions, like cardiovascular events with rofecoxib and Stevens-Johnson syndrome with valdecoxib
, has compelled their withdrawal from use .
Brown, "Effects of valdecoxib
in the treatment of chronic low back pain: results of a randomized, placebo-controlled trial," Clinical Therapeutics, vol.
Carter et al., "4-[5-Methyl-3-phenylisoxazol-4-yl]-benzenesulfonamide, Valdecoxib
: a potent and selective inhibitor of COX-2," Journal of Medicinal Chemistry, vol.
These include rofecoxib (Vioxx), valdecoxib
(Bextra), and sibutramine (Meridia).