Displaying 1 results of Rofecoxib Stable Isotopes Rofecoxib stable isotopes are non-radioactive forms of the drug rofecoxib that have a stable nucleus and do not decay over time. These isotopes are used in medical research to study the pharmacokinetics and metabolism of the drug, as well as to develop new methods for drug analysis and detection. Rofecoxib is a selective COX-2 inhibitor that was used to treat pain and inflammation, but was withdrawn from the market due to safety concerns.