The Prescribing Information for <"http://www.yourlawyer.com/practice_areas/defective_drugs">Rapamune has been modified regarding changes in the performance of an immunoassay used for monitoring the drug.
Rapamune oral solution and tablets are indicated for the prevention of organ rejection patients 13 years of age or older who have received kidney transplants. For patients who are taking Rapamune, it is recommended that therapeutic drug monitoring be performed, and several immunoassays have been developed for this purpose.
According to a “Dear Health Care Provider” letter issued by Wyeth Pharmaceuticals, the IMx immunoassay platform may yield results with a negative bias relative to the reference assay HLPC/MS/MS. This may vary from one laboratory to another and may also be affected by whether fresh or frozen blood samples are utilized. Switching between platforms, whether between immunoassay platforms or between immunoassay and HPLC, can produce differing results that may be clinically significant.
Given this information, Wyeth has made several changes to the prescribing information for Rapamune.
Wyeth is advising healthcare professionals to determine:
which assay is being used in their laboratory;
if there is any change to the assay used;
if there is a change to the laboratory’s reference range and/or a subsequent change to the institution’s or referring center’s recommended range for Rapamune.
By following these recommendations, Wyeth says target levels can be appropriately adjusted in order to achieve optimal clinical results.