Rapamune (sirolimus): Drug Monitoring Recommendations
MedSun: Newsletter #45, February 2010

FDA MedWatch Safety Alert

Wyeth notified healthcare professionals of changes to the Rapamune Prescribing Information regarding changes in the performance of an immunoassay used for therapeutic drug monitoring (TDM) of sirolimus. The TDM results reported from the assay are both assay and laboratory-dependent. In addition, the results may change over time. Therefore, adjustment to the targeted therapeutic range must be made with a detailed knowledge of the site-specific assay used. It is critical that the clinician caring for a patient on sirolimus maintain communication with their laboratory to determine whether the assay used for measuring sirolimus concentrations has been changed.

Additional Information:

FDA MedWatch Safety Alert. Rapamune (sirolimus): Drug Monitoring Recommendations. January 11, 2010.
http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm197059.htm